We trudge through the rubble of the Trump era’s bleak landscape hoping we’ve hit the nadir, only to find that there is no rock-bottom in the havoc that the US President is capable of wreaking.

The ides of October are deepening this impression. With just weeks to go before the midterm elections, which will either sustain or capsize Donald Trump’s control over Congress, one might expect him to hone his normally sharp populist instincts, but in fact his wits appear to have dulled with age and the pressures of high office.

The moment’s suspense is thus heightened: Are we on the cusp of a new era, when a Democratic House and Senate might restore some sense and balance to American politics — or will Republican victories lock the country and its allies into two more years of still deeper despair?

Several of Trump’s eye-popping actions this month have been well covered in the press. On Friday night, he issued an executive order blocking sanctions and tariffs against Russia 48 hours before they were due to take effect.

It came just days after he made an alarming deal whereby his friend Vladimir Putin agreed to export 300,000 tons of diesel fuel to the US and any other country that wants it.

The deal violates a US law, passed in 2022 after the invasion of Ukraine, banning the import of Russian energy supplies, and has been condemned by allied leaders – and even a dozen Republican members of Congress – as a scandalous “gift” to Putin, ignoring his continued attacks on Ukrainian civilians.

Trump publicly thanked Putin for the concession and, as a further outrage, condemned Volodymyr Zelensky for bombing Russian oil and gas targets – even going as far as to blame Ukraine’s President for the global energy crisis, when everyone knows the main cause is the US-Israeli war with Iran.

Meanwhile, the Trump-Putin deal, if it actually happens, will shovel billions of dollars into Russia’s war machine – a fact that is aggravating the rupture in transatlantic relations and alienating members of Trump’s domestic political base.

The irony here is that the US President could have struck a similar deal with Canada and acquired the fuel far more quickly. But he can’t do that because, as he’s growled several times, Canada is the new enemy, posing a bigger threat than Russia or China. While the claim is preposterous, Trump can’t bring himself to admit that he was wrong.

A bigger, more globally significant betrayal – but one less reported and certainly underanalysed – came a few days earlier, when Trump evacuated all 12 of the US Air Force’s B-1 bombers from RAF Fairford in Gloucestershire. He did so in response to intelligence reports that Iran was plotting an attack on the planes, though it remains unclear whether this attack would come from saboteurs or drones.

As a narrow issue, the retreat was unnecessary. A handful of suspected saboteurs in the area were arrested, and MI5 analysts privately expressed doubts that Iranian drones had the range to reach Fairford. But it was surprising.

Fairford had been a base from which B-1s attacked Iran earlier this year, and Iran had long threatened retaliation against such sites. US military commanders – and this is a criticism that goes well beyond Trump – should have taken steps to mitigate, prevent or pre-empt such threats. Here is yet another case – the entire course of the Iran war being another – where some of the most powerful weapons in the most powerful nation’s arsenal have flaked out in confrontation with a third-rate military.

But the broader implication of this retreat is far more significant. America’s defence posture – its ability to project power, deter threats and fight wars if necessary – depends on its vast network of overseas military bases. “Vast” barely begins to describe the extent of this network. It consists of 110 permanent bases in 43 countries, and hundreds more facilities that the US has agreements to lease or temporarily occupy in case of a crisis.

Without these bases, the US could not maintain its status as a global power with security commitments – or, as some might put it, imperial reach – on every continent. These sites allow American troops, advisers, spies, weapons, radar stations and other personnel and facilities to protect or, some might say, dominate the local governments. It also gives US commanders transit points for conflicts elsewhere.

Fairford’s role is not at all unusual. Bases throughout Europe, especially in Germany, were used as home sites, training grounds, repair and refueling stations, supply links and medivac hospitals for the wars in Iraq, Afghanistan and the various secret wars against terrorist organisations in Asia and Africa.

The bases also serve as highly visible signs of US commitment to defend allies and thus, if all goes well, to deter larger wars.

Here’s the point: If a US president decides to evacuate B-1 bombers from the UK in reaction to intel about a possible threat from Iran, what inferences might be drawn – by friends, foes and powers in between – about how the US will respond to threats by China against Taiwan, Russia against the Baltic states, North Korea against South Korea and Japan, or any other adversary against any other friendly territory?

Marco Rubio, the US Secretary of State, tried to wave off such concerns, telling reporters that the B-1s leaving Fairford were taking part in routine “rotations” having no relation to alleged threats. But Trump confirmed to reporters, as have anonymous sources since, that the planes were moved in response to an Iranian threat. His casual tone seemed to suggest that this was no big deal — though allies who view America’s global bases as guarantees of security might think otherwise.

This is why many leaders, especially in Europe and Asia, are scrambling to build up mutual defence pacts that don’t heavily rely on the United States. It’s why British and French leaders are thinking about linking their nuclear arsenals. And it’s why South Koreans and even Japanese, who have a strong historical aversion to nukes, are thinking about building their own bombs.

In the 1960s, experts predicted that roughly 20 nations would have nuclear weapons by the start of this century. One reason that didn’t happen was the superpower dominance of the Cold War. The US held open a “nuclear umbrella”, pledging to respond to an attack on its allies with its own nuclear weapons. Some allies quietly doubted this pledge, but stayed mum to hold the alliance together.

An exception was France’s Charles de Gaulle, who quite loudly doubted, as he put it, that a US president would sacrifice New York for London or Washington for Paris. He built his own small arsenal as a deterrent. Now Trump has given all his allies a fresh reason to wonder about America’s umbrella.