Iran’s willingness to escalate this high-stakes war is its greatest weapon

Regime will do whatever it takes to cling on to power – including sacrificing economies of other Gulf statesMiddle East crisis – live updatesBrinkmanship, the ability to take a country to the edge of war without plunging it into the abyss, was the cornerstone of cold war diplomacy. But in our different, more unstable times – in which the line between state and non-state actors has blurred, and weapons of war have diffused – the world this week finally tipped over the edge, and suddenly it is in freefall.The first six days of the Iran war cost the US $12.7bn (£9.5bn), but now the Pentagon is seeking as much as $200bn in military funding. Oil at $125 a barrel is no longer an Iranian, or Russian, fantasy. The crown jewel of Qatar, Ras Laffan – the world’s largest liquefied natural gas plant – may not reopen fully for five years, at a cost of $20bn a year. Other combustible oil depots in the Gulf, from Bahrain to Abu Dhabi, are exposed to Iran’s low-cost drones. Then add the human cost of