5th January 2020, The Sunday Times, by Michael Clarke.

The US drone strike on Qassem Soleimani was a shock tactic. It shocked the Iranians and the leaders of their proxy militia forces in Iraq, Lebanon, Syria and Yemen. It shocked outside powers such as Russia and Turkey; and it left America’s western allies — yet again blindsided by the White House — struggling to find policy responses to what looked like a reckless escalation in the standoff.

It was a typical Trump decision. Far from seeming to demonstrate weakness — a thin-skinned, impeached, president goaded into foolish mistakes in a difficult election year — his supporters recognise this as his signature move: unpredictable and bold. It unbalances the opposition and keeps everyone guessing.

But it is hard to see how it will work to America’s advantage, because it is not clear what endgame the US is pursuing. Donald Trump maintains that the Iranian leadership is close to collapse as a result of his “maximum pressure” economic tactics; but he has now switched to dramatic military tactics that could strengthen that leadership.

The Iranians are little better at strategy. They react partly from fear at what threatens Shi’ite Muslim communities in the region, but they do it with aggression, murderous subversion and implacable opposition to the US and Saudi Arabia. Iranian leaders such as Soleimani loved the tactics of the fight, but with every tactical success the strategy for Iran’s security and economic growth became more obscure. And they vastly overplayed their tactical hand in recent months, assuming the US had become a paper tiger.

Strategy without tactics, it is often said, is a daydream. But tactics without strategy are nightmares. There is likely to be a great deal more noise to follow this extrajudicial killing, before US and Iranian leaderships both face the strategic nightmare haunting each of them. The events of the past few days are very unlikely to lead to outright war; the Iranians couldn’t handle one, and it’s the last thing Trump wants as he pitches for a second presidential term. But the wider effects of Soleimani’s killing may nevertheless lead to the biggest “hybrid war” the world has witnessed.

The Iranians will probably choose different times and places to retaliate against US and western interests across the Middle East and perhaps beyond. This could include regional terrorism, cyber-warfare and domestic subversion.

But reactions on the ground will be more immediate. Soleimani’s reputation, and the killing beside him of an Iraqi commander and government official, make it unlikely that US and other allies will be able to carry on assisting the Baghdad government much longer. The weakness of that government and re-emergence of Isis sleeper cells in the north suggest the country may fall again into chaos.

And as part of a hybrid campaign, Iran can be expected to repeat its efforts to internationalise the conflict by making the rest of us pay a price. Interference with Gulf shipping is again on the cards, more Hezbollah rocket attacks on Israel, attempts to target oil production to increase everyone’s economic pain, and particular attacks that stay below a full-war threshold but pick away at the security of US forces and those of its allies throughout the Middle East.

Iran exposed the inadequacy of Saudi Arabia’s national defences in the attack on the Saudi Aramco complex in September, and will be tempted to find other ways to humiliate Saudi leaders. Not least, Tehran might take more political hostages among foreign visitors.

The US has gamed out its own tactics in response to these possibilities — including quiet dialogue with Tehran if it desists. But we can expect robust defence of all US facilities in the region. There will be intensified pressure on allies to impose more sanctions on Iran and to ditch, finally, the Iran nuclear deal that the Europeans have been trying to keep on life support since the US left it. In this situation, Iran will be a nuclear weapons state all the sooner.

Herein lie the strategic challenges that Washington and Tehran face. This sort of hybrid warfare doesn’t offer a result; just endless tactical competition. Even tit-for-tat strikes on military facilities would greatly increase the dangers without bringing matters to a head. And hybrid conflict, because it covers so many sectors, is fraught with unintended consequences. If they somehow stumbled into a genuine fighting war, the US would win militarily, and leave itself with all, and more, of the political baggage it has been trying for years to ditch. The Iranians would just lose, and the region would still be no more stable.

Professor Michael Clarke was Director-General of the Royal United Services Institute from 2007-15.