Foreign policy is virtually absent from the election campaign. But if David Cameron had had his way, we could have been embroiled by now – more than we already are – in yet another Middle East war. As it is, his Syria policy has still backfired, contributing to the rise of jihadism in our own back yard.

Cameron should not be let off the hook for supporting the armed opposition in Syria and being ready to start bombing Syrian government forces in 2013 after the Syrians had apparently used chemical weapons. The planes were ready to take off from Cyprus. It was only parliament, in a historic and too-soon-forgotten vote, that stopped this recklessness in its tracks. True, Syria subsequently disarmed itself of chemical weapons, but this was after the climbdown on bombing had shown western public opinion had no appetite for another war of choice. So it was no thanks to Cameron’s warmongering; it was, rather, a result of Russian pressure.

Did Cameron think that decimating the Syrian army would make life harder for the Islamists, palpably the bigger threat?

True also, Britain has gone on to join bombing operations against Isis. But it is one thing to bomb a rabble collection of fighters, another to bomb a regular army with an anti-aircraft capability. And what was Cameron thinking – that decimating the Syrian army would make life harder for the Islamists, who are palpably the bigger and more atrocious threat?

If Cameron had had his way, the jihadis could be in control of Damascus by now. Where is the accountability? William Hague took the fall for the embarrassing failure with parliament – after a decent interval he was removed from the Foreign Office – but Cameron is the Teflon man here. Having got away with bombing Libya (with barely a thought for the poor Libyans, whose country is now a tragic mess) he must have arrogantly thought that Syria would make a nice encore.

This is all the more deplorable because Cameron’s unthinking policy on Syria can only have fuelled the rise of support for jihadism among British Muslim youth. To call for the overthrow of the secular Syrian government, to demonise it out of all proportion (and remember, this is the same President Assad who was having tea with the Queen in 2006), to predict its imminent fall, as Cameron and Hague were doing in 2012 and 2013 – and then to wail as though it was nothing to do with them when British Muslims set off to help hasten said overthrow – is inconsistent and nonsensical.

To this day our official position remains that Assad must go and the opposition should be supported. Photograph: Reuters TV/Reuters

If we have seen a rise in the terrorist threat in Britain in recent years, Cameron must be held to account for his share in creating the conditions in which it has happened. I would be surprised if the security services had not warned him of this only-too-predictable turn of events. Presumably he ignored them.

Since the debacle in parliament we have sung small on Syria. Even Cameron could belatedly see his gung–ho policy was a tar baby. Now we have a non-policy of saying nothing, shovelling aid at the humanitarian situation and tagging along on the Americans’ coat-tails. Yet to this day our official position remains that Assad must go and the opposition should be supported – as though there was a significant non-Islamist opposition today.

There may have been a significant non-Islamist opposition in the early days, before the withering of the Arab spring. But the Syrian “revolution” was quickly and predictably sidetracked and deformed by the much more powerful Islamists. And it’s no good claiming our support is “nonlethal”: this is still aiding and abetting. We also continue to support sanctions against Syria, even though sanctions, as usual, do little harm to the regime they are directed at. Indeed, they have done immense harm to the Syrian economy, with consequent humanitarian suffering. If we want to help Syrians, it would be a good start to stop making their situation worse.

The vote against military intervention was a perfect instance of how Britain can still provide a moral lead to the world

At the moment we are on the one hand arsonists, causing the situation to deteriorate by indirectly giving succour and encouragement to the Islamists and hampering Syrian government efforts to rebuild in pacified areas and destroying Syrian jobs. On the other hand we are firemen, hosing taxpayers’ aid money on to a humanitarian disaster that we are helping fuel.

Far from symbolising loss of spine, the parliamentary vote against military intervention in Syria was a perfect instance of how Britain can still provide a moral lead to the world without “punching its weight” militarily. It is no accident that the US Congress drew in its own bellicose horns after the historic vote in Westminster, where 30 brave Conservative rebels joined forces with Labour and others. Obama appeared relieved to be off the hook.

We will need to spend more on defence – more billions than we do already – if we have a government that is going to get us into reckless scrapes. And this is the point about David Cameron: it’s no good having a strong economy and a sound NHS if all this is going to be put at risk by a leader who bases his foreign, defence and internal security policies on little save arrogance, ignorance and wishful thinking.