James Gray is a member of the Joint Committee on National Security, Chairman of the Armed Forces Parliamentary Trust, and author of Who Takes Britain to War? He is MP for North Wiltshire.

Theresa May will need political support for whatever she does in reaction to the vile use of chemical weapons in Syria. If she gets it wrong, she will pay a heavy political price. However, any call for a Commons vote on the matter prior to any such military strike against Assad would both risk losing – as happened to David Cameron in very similar circumstances in 2013 – and would also abdicate the heavy responsibility for taking that kind of decision which ultimately must be hers and hers alone.

And were she were to seek ‘political cover’ from a vote in the Commons on the matter, she would also effectively be emasculating the right and ability of Parliament to scrutinise and criticise what she has done. She and the Cabinet must act as they see best – and Parliament will then have plenty of opportunity to discuss and criticise it. However, if backbenchers have been whipped into supporting that action then we are giving up the right to hold the Government to account after the event.

When Cameron failed to persuade the Commons to endorse his plan to bomb Syria in 2013, it was the first time in history that Parliament rejected a Prime Minister’s war-making intentions. For hundreds of years prior to that, acting under the ancient Royal Prerogative, military action had been a matter for the Prime Minister and Cabinet, with Parliament subsequently holding them to account for their actions. Parliament was “informed and advised” of their military decisions rather than “being consulted” on them. Yet in 2003, by a clever piece of Blairite Parliamentary emasculation, the then Prime Minister used his whips (and ours) to persuade a reluctant Commons to approve his pre-set plans, thereby preventing us from questioning or criticising them thereafter.

Now of course there will be self-styled democrats and parliamentarians who will argue that such votes have great merit in strengthening Parliament against the Executive. ‘How can it be,’ they ask, ‘that that most important of all decisions – to go to war – should be decided not by the tribunes of the people, but by the Prime Minister acting under devolved powers from the Monarch?’ David Cameron and William Hague had been at the forefront in making exactly that point, which is no doubt why the then Prime Minister felt it so necessary to take the putative Syria action to a vote.

Yet the truth is that if use of military force is allowed to be political (which it must be, if it needs a majority in a possibly marginal House of Commons), then it cannot be strategic. Should the Prime Minister be doing what is right for the peace and the people of the world? Or should he have primary concern for its popularity in Parliament?

Giving Parliament the final say over warfare politicises the war in question; it means that possibly sensitive intelligence has to be made public; it removes any element of surprise, delays decision making, and in a host of other ways makes the effective conduct of military force extremely difficult, if not virtually impossible. Now even if you think that this may be a good thing, I hope that you agree it also has a devastating impact on our ability to project power for the good of the world. Diplomacy without arms is like music without an orchestra.

In other words, would it not be perfectly reasonable for the Prime Minister to authorise air strikes against Assad, and to have to inform Parliament of it, and answer our questions and criticism afterwards? Should Parliament’s job not be to hold the Prime Minister and Executive to account for what they have done rather than becoming a party to it?

In the longer term, should we not be setting the brains of the best constitutional lawyers to work to square the circle of giving the Prime Minister the necessary freedom to act militarily while still ensuring the primacy of Parliamentary decision making? Would it not be better for the ‘Royal Prerogative’, which Prime Ministers relied on so effectively in dozens of wars over hundreds of years, to be replaced by a ‘Parliamentary Prerogative.’ Parliament would write into law the acceptable reasons for military action, the ways in which wars should be fought, and the ways in which they should be concluded. (The three parts of the old philosophy of the ‘Just War’). Such a Statute would then allow the Prime Minister to act as he always done. He would be doing so with the full authority of Parliament, yet removing the necessity to consult we backbenchers in detail about the proposed military action.

But for now, lets us hope that the Prime Minister will have the courage to do what she believes to be best – for humanity, for Syria and for the world; to do so without seeking any kind of vote in Parliament; but then of course being ready to justify what she has done immediately, and in full.