IN dark times, begin by giving the Prime Minister a bit of credit. Unlike a certain predecessor, David Cameron has accepted that there needs to be an honest, public argument over the case for an escalated war in the Middle East.

He wants consensus. Reasonably enough, he doesn’t want to lose another Commons vote. Since he is smarter than some, Cameron also understands that Tony Blair’s approach to the invasion of Iraq was disastrous. If a Chilcot Report were to hand, we would all know it. Cameron’s devotion to truth has limits, however.

The same could be said about his 36-page “memorandum” in response to the Foreign Affairs select committee’s report on the “Extension of Offensive British Military Operations in Syria”. Clearly, Cameron put time into the paper. Even when run through the Whitehall filter, there is that “passion” for what he calls “doing the right thing”.

It’s an old trick. Dissent and you could sound, like the Scottish National Party or Dennis Skinner, as though you prefer to do wrong, that you are morally questionable, probably disloyal, a Chamberlain to the PM’s Churchill.

The trouble with old tricks is that most saw through them long ago. The UK intends to be ethical? Fine, we all have lists. On mine there is China, the Saudis, Bahrain, Israel ... and then some. When does bombing begin? Or, to be serious, why is it now of fundamental importance for the UK to become offensive, as generals say, in Syria?

Cameron’s document and his attempts on Thursday to answer the questions of 103 MPs differed, here and there, but the fundamentals were simple: Islamic State (IS) is disgusting, dangerous, and unconquered. We (the UK) should have more pride than to allow others to do the dirty work. Besides, our allies would feel happier with the Royal Air Force involved. And what’s a little bit of escalation?

As I mentioned last week, there has been no shortage of bombing since Operation Inherent Resolve was launched in August 2014. To quote the latest from the US Department of Defense: “As of 3.59 pm EST Nov. 19, the US and coalition have conducted a total of 8,289 strikes (5,432 Iraq/ 2,857 Syria).” Despite that, the best the Pentagon has ever claimed is “stalemate”.

Of 8,289 strikes, just 260 have been against “oil infrastructure”. That’s an odd discrepancy, given common knowledge of the fact that IS depends on petro-dollars. Will the RAF therefore be putting the terrorists out of business by destroying oil fields owned by Iraq and hocked to Western multinationals? Will the UK discomfit a Turkish regime that buys IS oil while it bombs Kurds who provide the only serious ground opposition to the terrorist state?

It’s complicated. Complications are a nuisance when you mean only to do the right thing. Among the odder complications are that IS and Israel have never exchanged a shot, that “valued Nato ally” Turkey is setting ambushes for Russians, and that the UK’s prime minister wants you to believe a marginal involvement in bombing will make us all safer.

He maintains, meanwhile, that there are “70,000 fighters” ready to fight in places to which the UK, the US and France will not send troops. This, Turkish attacks on the Kurds aside, is a nonsense unless we mean to give free rein to the dictatorship of Bashar al-Assad, the thug we were supposed to be bent on overthrowing the last time Cameron lost a vote on Syria. Where are those “regional forces”? Last week, our PM was vague.

Terrorism is a well-established field of study, but two things have altered since IS came along. Once is the zealots’ devotion to the idea of a caliphate. That – setting aside multiple abuses of history – requires a physical, governmental entity, a “state”. In the past, most terrorist insurgencies cared little for territory. Sticking up a black flag on a building only creates a target. But IS is doggedly naïve about that.

Its insurance is the net, the virtual world in which you can invent a caliphate and back up fantasy with slaughter in a concert hall. Cameron says we will become safe – but not instantly, as he admits – if bombers pulverise a physical IS state-entity and destroy its credibility among young Muslims susceptible to millenarian revenge fantasies. He’s mistaken.

The contrast between fighter-bomber reality and online jihadi clamour is a matter of alternate realities. The handful involved in the Paris murders were not deterred by 8,289 strikes. Their siblings will not be restrained by the RAF in years to come. The UK is, as Cameron has been honest enough to concede, already a “first-tier target”. Bomb IS a little more and they will respond in kind. That’s war; say so.

The Prime Minister asks that we “do the right thing”, make ourselves safe, stabilise a region, reclaim a homeland for refugees, spend £1 billion to repair damage, stand by our strategic alliances, and – you cannot fault him for ambition – begin to extirpate the bloody physical expression of a medieval argument over faith. In 1939, we went into world war thanks to a Polish-British defence pact.

The Foreign Affairs committee set Cameron a handful of tests, seven in all. The first is basic: will UK involvement allow “the coalition” to make things better in Syria? Cameron asserts that if we destroy IS on its claimed turf, all else – security at home, Assad’s “transition” to retirement, an end to jihadi hatred – will follow.

You could call that a stretch. You could also say it is the last shout of a country with an excess of 20th-century killing machines still refusing to comprehend what “threat” means in the 21st of Christian calendars. Then you could ask, before we drift into patriotic war, why Cameron does not promise to wipe out IS in the oil business, in banking, and in the global arms trade.

In the Commons last week, in passing, he nodded at that. But when old Skinner asked about the Turks and oil deals, the language for “doing the right thing” eluded Cameron. The “transition” for Syria and its millions of refugees? That “regional support” from the Turks, the Saudis, or Iran? A plan for the aftermath? An actual battle strategy? The UK’s particular value in all of this?

For Cameron, arguments are reduced to the belief that we, in these islands, should – and therefore must – be doing “something”. He does not accept that something could be worse than nothing. In his world of flags and big bangs, it is our obligation to stand against barbarians. Yet not – if we can possibly help it – disturb oil markets by cancelling the IS petro-cash card.

We are stumbling into a war that will be as peculiar as it will be bloody. We understand neither the enemy, nor our aims. We do not even understand what victory would look like. We guess, with plenty of experience of terror, that it will not make us safe. The last Daesh killer killed will not be the end of it.

Bomb Humvees because you have no better idea? Those who vaunt the UK can surely to God do better than that.