Here is a good 500 word summary from the BBC with pictures and maps to help some folks understand why this is happening. Some of you have asked me in the comments to give you some background on the war so here you go.
The Caucasus are a strategically important mountainous region in south-east Europe. For centuries, different powers in the region – both Christian and Muslim – have vied for control there.
Modern-day Armenia and Azerbaijan both became part of the Soviet Union when it was formed in the 1920s. Nagorno-Karabakh was an ethnic-majority Armenian region, but the Soviets gave control over the area to Azerbaijan authorities.
The Armenians in Nagorno-Karabakh made several calls to be transferred to Armenian authority control in the following decades. But it was only as the Soviet Union began to collapse in the late 1980s that Nagorno-Karabakh’s regional parliament officially voted to become part of Armenia.
Azerbaijan sought to suppress the separatist movement, while Armenia backed it. This led to ethnic clashes, and – after Armenia and Azerbaijan declared independence from Moscow – a full-scale war.
Tens of thousands died and up to a million were displaced amid reports of ethnic cleansing and massacres committed by both sides.
Armenian forces gained control of Nagorno-Karabakh before a Russian-brokered ceasefire was declared in 1994. After that deal, Nagorno-Karabakh remained part of Azerbaijan, but since then has mostly been governed by a separatist, self-declared republic, run by ethnic Armenians and backed by the Armenian government.
It also established the Nagorno-Karabakh Line of Contact, separating Armenian and Azerbaijan forces.
Read the rest of the story at the BBC.com.