What does Russia's troop call-up mean for Ukraine?

Russian President Vladimir Putin has ordered a partial mobilisation to reinforce his troops in Ukraine after major combat setbacks this month. In an address to the nation, he

said Russia was directly threatened with "disintegration" by the Western powers backing the Kyiv government. He also warned Nato that nuclear-armed Russia could use any

weapons in its armoury against what he called Western "nuclear blackmail". His message came a day after Russian-installed leaders in four regions of eastern and southern

Ukraine announced plans for so-called referendums - starting this week - on joining Russia. Crimea was annexed by Russia after just such a move in 2014.What does this

mobilisation mean in practice? Russia plans to call up about 300,000 reservists - that is, people who have had military training and, Vladimir Putin stressed, have specialist

skills needed in the Ukraine conflict. They will include many reserve officers, including some over 60, pulled in from retirement. Russia could in theory mobilise some 25

million people for military service, but that is not yet being considered. Both President Putin and Defence Minister Sergei Shoigu stressed that conscripts would not be sent to

fight in Ukraine. Mr Shoigu said the extra troops were required to defend a front line stretching for some 1,000km (600 miles). The mobilisation will be spread over

months - and Mr Putin has said previously that Russia is prepared for a long fight. Reuters news agency says it is Russia's first mobilisation since World War Two, but the Kremlin

did send thousands of conscripts to fight in Afghanistan in the 1980s, and later in Chechnya, in the North Caucasus.