Where’s Boris Johnson? It sounds like some dreadful party game, and Jeremy Corbyn wanted to play it.

He insisted the Prime Minister was hiding behind the Defence Secretary. We gazed at Ben Wallace, a chunky figure in a Brigade tie, but surely not chunky enough to hide Johnson.

There were, it is true, plenty of Tory MPs behind Wallace, pretty much filling that side of the House, but many are new, so as yet unknown, and none bore the slightest resemblance to the party leader who did so much to get them elected.

Corbyn ventured a joke: “I’ve long spoken out against the Iranian government’s human rights record.”

The Tories erupted in heavy, mocking laughter, old hands showing the new recruits how this is done.

The Leader of the Opposition said “the law is that we don’t go around assassinating foreign leaders”. He wondered whether the British Government thought what the Americans had done was legal.

It sounded as if Corbyn suspected Donald Trump was hiding behind the Defence Secretary too.

This was not what Wallace thought. He said America had acted in self-defence, a right in which Britain very much believes, but it was “for the United States to answer about the intelligence” on which the killing of General Soleimani had been based.

The Defence Secretary launched a counter-attack on Corbyn, whom he accused of spouting the usual anti-American sentiments and “anti-imperialist guff”.

There is a lot of anti-imperialist guff around. The late Julian Amery (Con, Brighton Pavilion) used to support the maintenance of an imperial system of control in the middle east, and to think that the Americans had made a bit of a mess of things when they took over from the British and the French, but Wallace decided discretion was the better part of valour, and did not treat us to the pro-imperialist case.

On the question of Johnson’s whereabouts, the Defence Secretary assured us the Prime Minister is running the country, something Corbyn will never do.

Wallace added that “the Prime Minister actually believes in Cabinet government”. That is a doctrine all Prime Ministers believe in to begin with.

Tommy Sheppard (SNP, Edinburgh East) wondered whether there were any other Iranians “whose assassination the United Kingdom would find acceptable”.

Wallace indicated that he found this question in rather poor taste. Unfortunately, on this occasion a “kinetic or lethal strike” had been required, but it was not, he implied, the sort of thing he wanted to see every day of the week.

Simon Hoare (Con, North Dorset) wondered whether President Trump was “alert to the Pandora’s Box he has potentially opened”.

Wallace did not offer a direct answer to that question. Soon he was declaring that “our hand of friendship is there for the people of Iran”. Further conflict is in no one’s interests, added to which it is not actually American policy to destroy Iranian heritage sites.

Whether in Tehran, or in the White House, so peaceable an outlook prevails, Wallace did not venture to say.