Theresa May faces some tricky questions in the Commons later today.  She will say that Britain was right to take military action against the Assad regime, but will not add, at least if her previous statements are anything to go by, that it was definitely responsible for a chemical attack in Ghouta.

She will add, rightly, that the Government was under no obligation to win the Commons’ approval before authorising the missile strikes.  But MPs will know that this was not the main reason for her deciding as she did.  Donald Trump and Emmanuel Macron would not have been prepared to wait for them to make up their collective mind before ordering their armed forces into action.  And the Prime Minister was unwilling to be left behind – not when she wants, for Brexit-related and other reasons, to demonstrate that we will stand with America, maintain hard power parity with France, and remain a Global Britain.

May will also say that the attack was legal.  She will be pressed on the point, perhaps particularly over her reference to the attack in Salisbury, to which she alluded in her statement made in the immediate wake of the strikes.  That will be hard to square with the Attorney-General’s judgement that the bombing was justified on humanitarian grounds.

However, circumstances also favour the Prime Minister in a number of ways.  MPs critical of her decision will in effect be arguing that the stable door should be closed after the horse has bolted – or rather, strictly speaking, after it has returned to the stable, now that the military action is ended (at least for the time being).  That weakens their leverage.  Furthermore, the strikes will not, as their equivalent in 2013 might have done, tilt the Syrian civil war against Assad.  Strange as it may seem, that will help May this afternoon: MPs will not be able to claim that the struggle has been tilted in favour of ISIS or Al Qaeda-aligned jihadis.

It could be that Russia will now strike back in asymetric ways – through cyber attacks, for example.  A cynical take would be that neither it nor America will let Syria spark a potential third world war, and that James Mattis calibrated the Trump administration’s action shrewdly – avoiding any direct confrontation with Russian forces.

The Prime Minister will also be aided by the unwillingess of Conservative backbenches to line up with Jeremy Corbyn.  But if he succeeds in winning a vote on Commons pre-authorisation of military action, it could just be that a handful of Tory MPs are persuaded into the opposition lobby.  However, the odds against such an outcome are long.  This site’s judgement before the strikes was that, in raw political terms, May could get away with them – without a Commons vote.  We will see this week whether that was right.  The Prime Minister will doubtless want to move the collective conversation on, stressing a new diplomatic push to rid Syria of chemical weapons.