The growing presence of Russian troops in the southern Ukrainian peninsula of Crimea has raised the concerns of the acting Ukrainian government and the international community. Ukraine now says that Russian forces have taken control of strategic military sites in Crimea, and that the situation could quickly escalate.

This is not the first time Russian troops have been deployed to one of the former Soviet states. Here is a quick recap of the Russian military’s most significant activities since the early 1990s:

The Russia-Georgia war 

South Ossetia

A Russian peacekeeper stands near his BMP-1, infantry fighting vehicle, at a checkpoint in Tskhinvali, capital of the separatist Georgian province of South Ossetia in this Friday, July 23, 2004 photo. (AP/Shakh Aivazov, File)

In 2008, a five-day war broke out between Russia and the former Soviet republic Georgia over the breakaway regions of South Ossetia and Abkhazia. Tensions had been simmering since the early 1990s, when violent conflicts took place in those regions, prompted by South Ossetia and Abkhazia’s demands for independence from Georgia. In each case, Russia supported the separatists.

Wanting to reclaim the breakaway territory in South Ossetia, Georgia launched a military attack in August 2008, saying that its peacekeepers in the region had been attacked. Russia responded by sending its own troops to the area and launching airstrikes. After five days, a peace agreement was reached, but tensions continued to linger.

The conflict in Chechnya

Chechnya

Russian troops patrol past damaged houses in Grozny, Chechnya, in this April 13, 2005 photo. (AP /Musa Sadulayev)

Chechnya, a southern Russian republic in the troubled Caucasus region, has been trying to break away since the collapse of the Soviet Union. Russian troops and Chechen rebels fought in the early-to-mid 1990s, before the conflict escalated in 1999.

Members of an Islamist militia from Chechnya crossed into the neighbouring Russian republic of Dagestan in August 1999, offering support to that region’s separatist movement.

Then-prime minister Vladimir Putin sent troops to Chechnya in response. The republic’s capital city, Grozny, was nearly destroyed. Tens of thousands of people were reportedly killed over the course of the two Chechen wars.

Chechnya was eventually given some autonomy from the Russian government, but remains a part of the country and is under Moscow’s control.