Readers will have noted that the Prime Minister did not claim categorically, in her statement about military action in Syria, that the Assad regime is responsible for the chemical attack in Doura.

Her words were: “a significant body of information including intelligence indicates the Syrian Regime is responsible for this latest attack”.

Theresa May is being cautious – understandably so since, if the regime was responsible (and no other explanation is persuasive), the Russian military will have cleansed the area of evidence, or will have tried to, before UN Organisation for the Prohibition of Chemical Weapons inspectors get to work.

Instead, the Government’s core argument is that Assad has “a persistent pattern of behaviour” with chemical weapons.  (In which case, some might say, since he is winning Syria’s civil war, “bit late now”.)

Note, too, how she deployed the attack in Salisbury in making her case: “We cannot allow the use of chemical weapons to become normalised – within Syria, on the streets of the UK [our italics], or anywhere else in our world.”  That’s the Prime Minister’s way of joining up Russian responsibility for the oversight of the use of such weapons here and abroad.

She referred to a “limited and targeted strike”.  But what happens if the Syrian regime makes another chemical attack in the near future?

That’s a question which, among others, this site has repeatedly asked.  It will be worth watching how some Conservative MPs react in the Commons on Monday, torn between reservation about military action and unwillingness to line up with Jeremy Corbyn.

In particular, it will be important to try to get a sense of how many of these there are.

For most Tory MPs, the issue about Commons pre-authorisation of military action will surely have come and gone.  But Monday will provide the first opportunity to get a sense of how many are, as it were, on the Tom Tugendhat wing, supporting action enthusiastically, and how many on the Julian Lewis wing, out of sympathy with it.