Woe to he who inhabits the in-between, for his fate is not his own but is determined by the strength of his neighbors. So it is with the Caucasus, the land that sits at the intersection of Russia, Turkey, Iran and their historical empires.

More than a highway and battleground, the Caucasus is a borderland, which means that it plays a far outsize role in world history relative to its size and population (about 16 million). For 100 years, the oil reserves in Azerbaijan made the Soviet Union a continental and then a global power. The largest battle in human history in terms of number of people involved and killed, Stalingrad was the Soviet Union’s last stand against Hitler’s attempt to reach those oil resources to starve the Soviet military machine of its ability to wage war. It was Stalin – a Georgian, not a Russian – who seized control of the Soviet Union in 1922, setting the stage for events that defined the 20th century.

It was also the Caucasus that showed the world the true extent of the Soviet Union’s weakness as it approached its end. Both the rise of Georgian nationalism at the end of the 1980s, which was anti-Soviet in nature, and the failure of the Soviet Union to prevent a small region in Azerbaijan called Nagorno-Karabakh from seceding and joining Armenia marked the end of the bloc, and with it a 500-year epoch in which at least one of the world’s major powers resided on the European continent.

This Deep Dive is the first of two on the Caucasus. It will focus on the South Caucasus, the region below the Greater Caucasus mountains that includes present-day Georgia, Azerbaijan and Armenia, as well as the de facto states and contested territories of Abkhazia, South Ossetia and Nagorno-Karabakh, and the uncontested but detached region of Nakhichevan. Part two will focus on the North Caucasus, which now exists within the southern bounds of Russia. But the South Caucasus, a strategic buffer to Russia, Turkey and Iran, has never truly been tamed.

A Land Bridge From the Black Sea to the Caspian Sea

Were it not for its mountains, the Caucasus would be a 300-mile-wide (480-kilometer-wide) land bridge between the Caspian and Black seas leading directly into the heart of Russia.

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Mountains, however, are the Caucasus’ defining geographical feature. Two ranges run through it. The Greater Caucasus, as the name implies, is the taller and more rugged mountain range. It spans nearly the entire length of the land bridge from the northeastern shores of the Black Sea to the Caspian, giving way to a low-lying plain only slightly west of Baku, Azerbaijan’s capital. Effectively, the Greater Caucasus is a nearly impassable barrier between Russia and the countries of the South Caucasus. Mount Elbrus, at 18,510 feet, is the tallest mountain not just in Russia but in Europe as well. To the south are the Lesser Caucasus, beginning in southern Georgia and curving southeast into Armenia, around Lake Sevan, and into the contested region of Nagorno-Karabakh.

Between the two mountain ranges runs the Kura River, creating a valley that empties into an increasingly flat plain as it flows east through Azerbaijan and into the Caspian Sea. In Georgia’s far east is a flat, fertile plain marked by temperate weather that makes it ideal for agriculture as well as winemaking. This east-west passage along the Kura and its flanking flatlands is one of the few strategic highways great armies have traversed through and fought over for millennia.

A picture taken with a drone on Aug. 22, 2017, shows the 6th-century Jvari monastery and the confluence of the Aragvi and the Kura rivers, about 9 miles from Tbilisi. VANO SHLAMOV/AFP/Getty Images

Historically, the Greater Caucasus has only two north-south passages through it, both of which are extremely narrow. The first is a strip of flat land along the Caspian coast from Baku to Dagestan through the Derbent pass, believed to be the site where Alexander the Great constructed a wall, the Gates of Alexander, to prevent the approach of “barbarians” from the north. The second, the Darial pass, runs through the center of the Greater Caucasus, from the Georgian capital of Tbilisi to Vladikavkaz, Russia. The ominously named Georgian Military Road weaves its way through the pass, running very close to South Ossetia, a fact that bestows outsize importance on the small Georgian semi-autonomous region. To Russia, the road is a major artery that could be used by an invading force to enter into its interior.

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A second highway, the Transcaucasian Highway, was built more recently by the Soviet Union in the 1970s and 1980s, directly connecting North Ossetia to South Ossetia for the first time in their history. It cuts through South Ossetia, giving it similar strategic value to the Georgian Military Road. It is a more perilous path, however, prone to closures in the winter.

Battleground Among Empires

Turkey, Iran and Russia have been fighting one another for centuries – back to a time when they were the Ottoman, Safavid and Russian empires. And where else would they fight but the land where their empires met: the Caucasus. The mountains between them, however, added a layer of complexity to war-making efforts, and it made the few traversable passages within the region invaluable.

The Ottoman Empire and the Safavid Dynasty (Iran’s predecessor) challenged one another in a series of five wars throughout the 16th and 17th centuries for territorial supremacy and command of religious loyalties of the Islamic world. Between their empires lay the Zagros Mountains, which today protect Iran’s western border. For the Ottomans to attack the Safavid Dynasty, therefore, they first had to move north into the Armenian Highlands – a 3,000-foot-high plateau to the west of the Lesser Caucasus and north of Lake Van, itself pockmarked with mountains – and then southwest into Iran. Control of Tabriz, which was the capital of the Safavid Dynasty at the time and which sits in northwestern Iran, changed hands between the two empires several times, ultimately leading the Safavid shahs to move the capital east, first to Isfahan and then to Tehran.

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But just because they fought often does not mean the fighting was easy. The mountainous terrain of the Caucasus is unforgiving, frozen for all but a few months out of the year. All military objectives had to be accomplished before winter broke the supply line and stranded the army without food or munitions. Retaining the territorial gains of each campaign was impossible. It was also critical for both militaries to secure the support of local tribes in the Caucasus, which would otherwise constantly threaten lines of supply. By themselves the tribes were relatively powerless, but their support was indispensable for empires trying to maintain armies in the field.

The Ottomans and the Safavids waged war intermittently for 130 years, only to have winter come and wipe the slate clean. Finally, in 1639, they signed the Treaty of Zuhab, which set boundaries between their empires that are essentially the same as the modern borders of Iraq and Turkey (which at the time were part of the Ottoman Empire) and Iran.

Russia’s primary interest in the Caucasus is to protect the plain to the north of the Greater Caucasus that extends into the Russian heartland. Flat terrain is difficult to defend, and were an army to cross the Greater Caucasus through the Darial pass, it would represent a mortal threat to Russia. Russia’s last stand would have to be along the 400-mile stretch from Astrakhan to Rostov-on-Don. It’s far easier to block a single passage through a mountain range. This is why the Darial pass and the Georgian Military Road that runs through it are so vital to Russian security. Though Russia would like to exert as much power south of the Greater Caucasus as possible to give itself an even deeper buffer, control of the area immediately to the north is critical, for above that the plain juts like a dagger into Russia’s soft underbelly.

Following the reforms of Peter the Great in the 18th century and the onset of the Ottoman Empire’s decline, Russia pushed south past the Greater Caucasus and challenged the Ottomans in a series of wars. Hostilities between the two powers were not new; 12 Russo-Turkish wars were fought between 1568 and World War I. But Peter’s consolidation of the Russian Empire and his military reforms enabled his successor, Catherine the Great, to begin to take greater control over the South Caucasus. The Russian Empire never fully controlled the South Caucasus as it did the North Caucasus, in part because of the difficulty of subjugating the mountainous clans and tribes that inhabit every corner and crevice of the terrain.

Nevertheless, from this point on, Russia gradually exerted greater influence over the region, albeit indirectly, at the expense of the Ottomans, culminating in the accession of the countries of the South Caucasus into the Soviet Union in the 20th century. They still retained a fair degree of autonomy, especially relative to other regions, such as Belorussia, that were utterly consumed by Soviet force. But Soviet oversight was enough to more or less keep the peace – through brutal terror – among the myriad rival ethnicities and religions in the Caucasus. Of course, it wouldn’t last.

Modern Countries, Modern Conflicts

The mountainous terrain of the Caucasus is isolating for the people who live there. Inhabitants are loyal to small social units, not to the other people who just happen to reside with them inside the invisible boundaries of a state. The modern South Caucasus contains just three countries – Azerbaijan, Armenia and Georgia – but they can’t even begin to accommodate all of the region’s different identities.

For example, Georgia comprises not only Georgians but also ethnic Abkhazians. Yet within Georgia, there is the semi-autonomous region of Abkhazia, home to ethnic Abkahzians – and ethnic Georgians. (The aftermath of the Abkhazia war in the early 1990s was confusing and tragic for the ethnic Georgians who fled Abkhazia. Thomas de Waal, a scholar who studies the Caucasus, calls this a “double stranger” experience. Ethnic Georgians born in Abkhazia were strangers in Abkhazia because they weren’t ethnically Abkhazian, but they were also strangers in Georgia because they were from Abkhazia and therefore unwelcome.)

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Armenia and Georgia consist primarily of Orthodox Christians, which has in the past evoked a degree of affinity between these populations and Orthodox Russia. This was especially true in the late 19th century, when the Russian Empire was at war with the Ottoman Empire, a Sunni entity. But even this harmony is complicated by pre-Christian pagan and Zoroastrian elements that infuse Orthodox Christianity in the Caucasus.

Azerbaijan consists mostly of Shiite Muslims, which creates some bonds with Shiite Iran. In fact, three times as many ethnic Azeris live in Iran as there are in all of Azerbaijan. But Azeris are also ethnically Turkic, and thus have an affinity with the Turks in Turkey as well. The Azerbaijani language is even similar enough to Turkish that speakers can generally understand one another.

Iran, with its large Azeri population, has been concerned that a version of trans-Azerbaijani nationalism may develop and that its 25 million ethnic Azeris will rise up and challenge the Islamic regime. But although ethnicity often encourages alliance, it does not guarantee it. The Soviet Union’s indirect control of Azerbaijan created divergent paths for Azeris living in Azerbaijan and those in Iran. Nevertheless, Turkey and Iran are countries with conflicting interests, and Iran remains wary that Turkey could use its large Azeri population against it. Shiite Iran, to balance against Turkey and Azerbaijan, is therefore currently closer to Orthodox Armenia than to Shiite Azerbaijan.

Nationalism Awakens Old Rivalries

As the Soviet Union declined and then fell in the late 1980s and early 1990s, nationalism surged in Georgia, Armenia and Azerbaijan as they all broke away from their Soviet overlords. The new state of Georgia sought to reacquire Abkhazia and South Ossetia, threatening Russian strategic interests. It was a threat that Russia didn’t tolerate for long. Azerbaijani nationalism brought it into conflict with Armenia over Nagorno-Karabakh, which had been allocated to Azerbaijan in 1921. War ensued in the early 1990s, and today the status of Nagorno-Karabakh is still unresolved. We’ll consider each of these conflicts in turn and discuss how the geopolitical interests of the surrounding powers shaped their outcomes.

Abkhazia and South Ossetia

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Abkhazia and South Ossetia are two semi-autonomous states within Georgia that are officially recognized by Russia and one another but hardly anyone else. Georgia continues to deny their existence, instead claiming that they are a part of its own sovereign territory.

Going back a bit in history, the Ossets are an ethnic group within Georgia that came to Russia’s attention when Russia began to push south through the Caucasus in the late 18th century. The Georgian Military Road runs through North Ossetia and into Georgia, only about two miles east of South Ossetia at its nearest point in Gudauri. The founding in 1784 of the city of Vladikavkaz at the northern edge of the highway was a testament to how determined Russia was – and still is – to control the route. Vladikavkaz eventually became the capital of North Ossetia and a major Russian fortress. Its name means “rule over the Caucasus.”

Since the late 1700s, Ossetia, unlike Georgia, has generally had a pro-Russia disposition. In 1918-20, when Georgia supported the Mensheviks – the anti-Bolshevik forces in the Russian civil war – the Ossets backed the Bolsheviks and declared loyalty to Russia. The Bolsheviks would later return the favor, granting South Ossetia relative independence within the Soviet Union as the South Ossetian Autonomous Region.

Abkhazia is similar to South Ossetia in that it is a semi-autonomous region within Georgia. It has a larger population than South Ossetia, has historically been wealthier, and has a low-lying coast that gives it access to the Black Sea – and makes it very desirable territory for Russia, which would otherwise have limited ocean access. Ethnically, it is more diverse than South Ossetia. It contains at least five major ethnic groups, and in 1989 – before Abkhazia and Georgia waged a 13-month war over the region’s status – ethnic Abkhazians comprised only 18 percent of the population, compared with 45 percent for ethnic Georgians.

When the Soviet Union dissolved, Georgian nationalism resurged, and the Georgians sought to reincorporate South Ossetia and Abkhazia into their sovereign territory as part of a new unified nation-state. (Rhetoric that described the people of South Ossetia not as citizens but as “guests” on Georgian territory worried the Ossets – rightfully, it would turn out – about the risk of ethnic cleansing.) Russia grew concerned that Georgia would try to seize the two regions, which would threaten the southern end of the Georgian Military Road and the Transcaucasian Highway, and thus Russia’s access to the South Caucasus, as well as its Black Sea access. So Russia supported their independence indirectly in the 1990s, and then directly in 2008.

What finally drew Russia in was the concern that Georgia would begin to receive greater support from the West. These fears became reality in 2004 when a pro-Western president, Mikhail Saakashvili, came to power. Saakashvili, fearful of Russia, supported Georgian membership in NATO – whose foundation was based on resistance to Russia. In an attempt to keep Georgia divided, Russia in 2008 began issuing Russian passports to inhabitants of Abkhazia and South Ossetia and recognized the heads of state of both regions. It wasn’t long before war ensued, starting when Georgian artillery units fired upon positions in South Ossetia.

When the war began, Saakashvili expected assistance from the United States, with which Georgia had been developing better relations. Russia came to the aid of South Ossetia and Abkhazia; U.S. assistance never came. Georgia, because of its proximity to Russia, matters much more to Russia than it does to the United States. This was the first major invasion launched by Moscow since the end of the Cold War, and it laid bare the limits of U.S. support in the regions of the world that are not critical to American interests.

Georgia was swiftly defeated, but its independence is still troublesome for Russia. Georgia itself does not have access to the region’s major oil fields, but its presence in the center of the South Caucasus puts it along a critical east-west transit route for oil pipelines out of the area. One pipeline carries oil from the Caspian to Turkey for export, beginning in Baku, traveling through Tbilisi and terminating in Ceyhan, Turkey. Similarly, a railway from Baku to Tbilisi to Kars, also in Turkey, is expected to come online by the end of the year (though there have been frequent delays).

Russia looks at these transit routes and sees danger. It fears that they will help Georgia grow its economic relationship with the West, thereby lessening its dependence on Moscow. Georgia, for its part, wouldn’t mind closer ties with the West, but its experience in 2008 taught it that there are limits to this partnership. The pipeline and railway from Baku to Turkey were deliberately designed to avoid Armenia — Azerbaijan wanted this because of their rivalry, and Turkey’s borders have been closed to Armenia since the Nagorno-Karabakh war  (not to mention that Armenia retains a foul historical memory of the genocide of its people by the Ottoman Empire during World War I). Landlocked Armenia is thus completely dependent on Georgia and Iran for its trade and access to the rest of the world. This includes trade with its ally, Russia – which Georgia can’t afford to aggravate too much. Therefore, in addition to preserving cordial ties with Azerbaijan and Turkey, Georgia must also be relatively friendly with Armenia.


Today, Nagorno-Karabakh is effectively controlled by Armenia, but its independence is recognized by no one, not even Armenia. In 1988, Nagorno-Karabakh, which at the time was a part of Soviet Azerbaijan, asked for its borders to be redrawn to be incorporated into Armenia. The Soviet Union refused, but in a demonstration of its impotence near the end, it was unable to control the situation in the face of rising Armenian and Azerbaijani nationalism.

When the Soviet Union broke apart and Armenia and Azerbaijan became independent countries, they went to war with one another over Nagorno-Karabakh. It was one of the bloodiest wars in Europe since the end of World War II. Twenty thousand people were killed, and nearly 1 million people were displaced out of a total Caucasian population of 16 million.

Russia at different times supported both sides of the conflict. But it’s difficult to tell what its role was exactly at the time, since control of the Russian military was quite decentralized, with many Russian soldiers participating in the war more as mercenaries. Nevertheless, today, Russia supplies arms to both Armenia and Azerbaijan. It is content with the frozen state of the conflict because it can use its ambiguity to put pressure on whichever country it needs to sway at the time. Formalizing any sort of resolution would deprive Moscow of this leverage.

Some believe that Russia’s strategy is to use Armenia’s heavy dependence on Russia to force it to vacate areas of Nagorno-Karabakh in exchange for concessions from Azerbaijan. Since Azerbaijan began exporting oil to Europe through the Baku-Tbilisi-Ceyhan pipeline, it has grown richer and less reliant on Russia. In exchange, Russia would demand that Azerbaijan join one of the multilateral economic or military institutions that it controls – the Eurasian Economic Union or the Collective Security Treaty Organization – pulling it away somewhat from the West.

Azerbaijan is unlikely to accept such an offer. The Azerbaijani security strategy right now hinges on its ability to balance between Russia, Iran, Turkey and the United States. Falling too heavily into one camp would decrease its flexibility. Further, Azerbaijan – whose population is predominantly Shiite – sees Sunni jihadists from Dagestan in the North Caucasus as a serious threat. If it were to pivot away from the West toward Russia, and Russia’s control over the North Caucasus were to decline, Azerbaijan could be caught between a Sunni insurgency at the northern end of the Derbent pass and Iran, which may use the occasion to expand its influence farther north into the Caucasus.


Lastly, there is Nakhichevan, an Azerbaijani exclave within Armenia. It, too, formed as a result of Azerbaijani nationalism during the fall of the Soviet Union. Though it is part of Azerbaijan and is recognized as such, at its closest point it is still separated from the rest of Azerbaijan by 30 miles of hostile Armenian territory.

Fighting between Armenia and Azerbaijan in the early 1990s nearly drew Turkey and Russia into their first major conflict with each other since World War I. Turkey worried that Armenia was planning to seize Nakhichevan, which shares an 11-mile border with Turkey, so it sent several thousand troops to the border. Russia responded by placing several thousand of its own troops who were already present in Armenia to the Nakhichevan-Turkey border. Whether as a result of this escalation or not, Armenia ultimately did not try to seize Nakhichevan, and both Turkey and Russia withdrew their forces.


The Caucasus is at the crossroads of empires. Those empires are long gone, but the interests of the countries that were at their core are unchanged. Iran and Turkey are far weaker than the Safavid and Ottoman empires were, but they’re still regional powers, and Turkey in particular is set to become much more powerful. Russia has tried for centuries to control the South Caucasus, but its only brush with success crumbled along with the Soviet Union. The North Caucasus, however, is a different story.