What won’t Boris Johnson do next? A new political season is about to get under way, and the prime minister’s agenda is packed with choices to defer and challenges to duck. There is always a back-to-school atmosphere at Westminster in the autumn, but it will be intensified this year by the resumption of parliamentary business unmuffled by Covid restrictions. The recall of MPs for a debate on Afghanistan in the middle of August was a reminder that politics has missed the volatile energy generated by a heaving Commons. For Johnson, who took a barrage of rebuke from his own side, it was a lesson in the solubility of Tory backbench loyalty. For the party, it was a showcase of their leader’s flaws. To the charge of being unready for the fall of Kabul, he looked guilty; his defence lacked gravitas. History came knocking and the prime minister answered the door bleary-eyed, slow to grasp what was being asked of him. Johnson has been doing the job for two years, but still seems surprised by the constant nagging of events. Meanwhile, Tory MPs are still surprised when their leader fails some test of leadership, as if they had not met him before and his reprobate tendency had been a secret. In fairness, neither Johnson nor his party could have anticipated the intensity of governing in a pandemic. It is not surprising that he looks depleted, nor is it unreasonable that he is taking a few days in the West Country before parliament reconvenes. (No 10 insists work will still get done remotely.) Downing Street then hopes to open a new chapter in the story, where great works delayed by Covid can be chronicled. The Cop26 climate summit in Glasgow in November gives Johnson a global platform to display leadership on an issue of epoch-defining importance. There is a neat tie-in with the domestic goal of “levelling up”. To repair ravages of the pandemic, Britain will “build back greener”. Johnson’s skill set comfortably extends to writing the speech that makes that sound easy. As first lord of the Treasury, he can also order a wad of public money to buttress the rhetoric. If there were only two steps in delivering effective government – making promises and writing cheques – Johnson would be on track for the transformational legacy he craves. But there are more, longer strides, which get harder to take because they go uphill and the way isn’t lined with cheering fans. That is usually where the prime minister’s attention fades. While Downing Street is dreaming of fireworks to dazzle the crowd, Rishi Sunak is fretting about the price of gunpowder. The economic recovery has so far outperformed the gloomiest forecasts, but the trajectory is uncertain. Britain also has a deficit of around £300bn, a comprehensive spending review due in the autumn, and a chancellor who takes a dim view of borrowing to maintain public services. That is a recipe for tension on multiple axes, as ministers resist cuts to their departments and MPs recoil from tax rises (especially ones that breach manifesto pledges). Policy disputes will escalate into public rows and briefing wars, made more poisonous by two of Johnson’s chaotic management techniques. One is issuing worthless promises in private, agreeing with whoever is making a case in the room just to bring awkward conversations to an end. Johnson is happy to let someone down, but rarely to their face. The other is reaching decisions by a process of attrition, letting underlings fight things out and hoping the passage of time will reduce the options until a viable path, perhaps the only one left, is clear. If the prime minister’s grip looks weak and the public mood is sour, the parade of cabinet dissent will evolve into a first-round pageant of potential successors. That won’t be because the incumbent is about to fall but because, in the Tory party, all it takes to ignite leadership speculation is a fleeting reminder that they all fall eventually. Even if Sunak strives to make himself as boring as possible, that effort will be talked up in the Commons and received on Johnson’s brooding, paranoid side, as a cunning plan to advertise the contrast between the two men – boring being code for dependable in an emergency. There is sure to be some kind of emergency, because that is the character of the times, and if things do settle down, Johnson’s negligent style of government will unsettle them again soon enough. He already appears to be done with the pandemic before the pandemic is done with Britain. Vaccines have lifted a burden from the NHS but not conferred immunity from crisis once seasonal pressures build and the backlog of deferred treatments still needs addressing. That is a foreseeable challenge. There will be surprises, too, demanding rapid reaction and executive competence supported by a strong cabinet. Without those conditions in place, it hardly matters what the prime minister thinks his agenda should be. He can choose what to talk about in the autumn, and persuade some audiences that he means it. But his powers run out almost as soon as the clapping stops. That is not a problem in election campaigns, where success can be measured in pleased crowds. But it is disastrous in government, where decisions must be taken with some other purpose in mind. The prime minister knows that he needs such a purpose, but not what it feels like to have one. The pandemic has been an exceptional event that would challenge any leader, but it is not the abnormal nature of the crisis that causes Johnson’s difficulties. He struggles because the way he does the job makes crisis the norm. Rafael Behr is a Guardian columnist