Why are Armenia and Azerbaijan fighting and what are the implications?

What is happening? Early on Sunday, Armenia announced it was declaring martial law, mobilising its army and ordering civilians to shelter. It claimed its neighbour Azerbaijan had launched a military operation inside a disputed region called Nagorno-Karabakh. Azerbaijan said it attacked only in response to Armenian shelling. Nagorno-Karabakh is recognised internationally as Azerbaijan’s territory, but has a mostly Armenian population who have resisted Azerbaijani rule for more than a century. In 1991, the region declared independence, and since then it has ruled itself – with Armenian support – as the unrecognised Republic of Artsakh. Map Despite signs in the past two years of possible...