Ukraine forces and pro-Russian rebels blame each other for attack outside eastern city of Luhansk
UK defence watchdog says major overhaul is required to defend against cyber-warfare and 'irregular militias'
Sanctions that tip Russia into recession only pile the pressure on Putin to grab what he can in Ukraine
European Union due to agree new sanctions after downing of flight MH17 and fighting in Ukraine
New measures risk a return to Cold War relations while some ask: why no action over Gaza crisis?
Obama accuses Russia of breaking Cold War test treaty with cruise missile launch
Russia says US and EU sanctions are 'absolutely unacceptable' and warns of reprisals
Cameron urges EU to punish Russia for links to separatists – but sanctions will hurt Europe too
For Putin, this is the worst collision between Russia and the West since the end of the Cold War
If Malaysia Airlines flight MH17 was shot down by a missile, it won't have been the first