However humane the cause for intervening against Bashar Assad may be, the old rules still hold
Cameron is warned by countless politicians and commentators 'this is not the moment to send arms'
Obama now said to be 'very, very hesitant' about arming rebels, while Boris Johnson calls it madness
Shrewd, cultivated and cosmopolitan new president knows that misery of daily life in Iran is the key issue
'There will be a curious and depressing symmetry for the UK if we get involved in this madness'
White House calls on Iran-backed Hezbollah to get out of Syria as battle for Aleppo approaches
France says blood and urine tests confirm sarin has been used 'multiple times' in bloody civil war
Putin must lead transition to post-Assad regime but there will be a price, says former Israeli PM
Fears that delivery of new weapons to Syria could spark new war and shift the balance of power
Better still, Cameron and Hague should stay out of it all together – it's none of Britain's business and we can't afford it
Britain succeeds in lifting EU's ban on sending arms to rebels, but opinion is split on possible outcomes
Video emerges showing man identified as Abu Sakkar mutilating corpse in Syrian 'war crime'
Assad's forces remain the most effective military formations in Syria and that's not about to change
Pledge of peace talks driven by fears that push to remove Assad regime is destabilising the region
Hardening evidence about Assad regime's use of chemical weapons prompts US re-think
Assad crosses Obama's 'red line' by using sarin gas, but president moving 'cautiously' to intervene
'Flash crash' caused by report that Obama injured in White House explosion
Experts say some fighters are jihadists, but Syrian opposition says numbers are greatly 'exaggerated'