“This is not our war.” That phrase, used by some European leaders to explain why they have refused to send forces to join America and Israel in their attacks on Iran, has become notorious in Donald Trump’s White House and has put the future of the transatlantic alliance in fresh danger.

The Iran conflict is not Japan’s war either, nor the war of anyone in the Indo-Pacific region. And yet everyone is being affected by that war. All are going to have to change their attitudes and assumptions as a result of the Iran war, in some small ways but also some major ones.

With the conflict still not resolved, following the unsuccessful negotiations in Islamabad on April 11th, it is too soon to come to final conclusions about what will be changed by the Iran war. The dramatic disruption that can suddenly be caused by war can equally suddenly disappear once the bombs and missiles go silent, which is probably why financial markets have not reacted as strongly as might have been expected. They are hoping that this war will be short.

However, some themes are already emerging that will indicate what kind of long-term changes are likely to result from the Iran war. Five issues have already become apparent.

The most worrying theme for the long term is the potential impact of this war on the proliferation of nuclear weapons. North Korea’s leader, Kim Jong Un, has boasted that, thanks to the nuclear weapons program successfully developed by his father and grandfather, his country would not have been vulnerable to the sort of attack that Iran has received.

It is likely that many members of Iran’s regime now wish that they had developed nuclear weapons more rapidly.

It is possible to argue that the Iran war will discourage nuclear proliferation – as attempting to go nuclear can justify an American attack – and that if only the Clinton or Bush administrations had had the guts to attack North Korea during the early stages of its nuclear program the world would be a safer place. Yet in truth it was always too dangerous to attack North Korea, especially given its close relationship to China.

In the Indo-Pacific there are already two nuclear-weapons states in India and Pakistan, in addition to China and North Korea.

The surprisingly open recent discussions in Japanese official circles about whether Japan should throw aside its nuclear taboo and develop a nuclear capability probably reflect concerns both that other countries, in particular South Korea, might do so soon and that the American promise of “extended deterrence” – keeping allies protected under its own nuclear umbrella – may no longer be sufficiently reliable.

A second emerging theme is related to that latter worry: questions arising from the Iran war about the strength and reliability of American-led deterrence in the Indo-Pacific against China, North Korea and Russia.

America’s war on Iran has put on full display the power and sophistication of its military forces. However what has been surprising is that in a war against an adversary that had already been greatly weakened by Israeli and American attacks in June last year, the American military so swiftly used up a high proportion of its stockpiles of its best weapons and missile-defence systems.

If this happens after just a few weeks of war against a weak adversary, how reliable can American deterrence be against a much stronger adversary, China?

Moreover, the war in Iran has entailed the transfer of ships, US Marine regiments, missile-defence systems and other assets from the Indo-Pacific into the Middle East.

The immediate gaps left by those transfers are not the main concern, although no military strategist in the Indo-Pacific can now keep out of mind the possibility, small though it may be, that the Iran war has created an opportunity that China or North Korea might be tempted to exploit.

The main concern is that, despite spending nearly US$1 trillion per year on defense the American military looks quite severely overstretched after just a short war.

Evidently, concerns that have been expressed in recent years about defense production capacity in the United States are valid. Yet what this also suggests is that too high a proportion of US defense spending may be going on fixed overhead costs such as US military bases all around the world and too little on nimble assets and on stockpiles.

A third theme from the Iran war is that it has taught many countries lessons about what defense against missile and drone attacks may really require in the future. The Gulf States of the United Arab Emirates, Qatar, Bahrain, Kuwait and Saudi Arabia have found themselves under repeated assaults from Iranian missiles and drones which their existing defense systems were unable to protect them from sufficiently well.

Part of the reason for this has been the global shortage of the sophisticated and costly missile interceptors used in American-made Patriot and THAAD defense systems that the Ukraine war had already exposed. But also the reason is that until now other countries have not had to learn from Ukraine’s experience in being attacked by swarms of low-cost drones. Now, demand for Ukrainian-style anti-drone defences is going to boom, and not just in the Gulf. Japan, too, should be investing in anti-drone defences.

An obvious fourth theme is the need for stockpiles and diversified supply-chains of energy and of critical minerals.

There has been plenty of analysis in recent years of “chokepoints” that could provide leverage to one side during a war, but the potential use of the Strait of Hormuz in this way was surprisingly downplayed or even ignored by the United States. Yet this narrow body of water, which is shared by Iran and Oman, had long been identified as a chokepoint, given that one-fifth of the world’s annual supply of oil flows through it in tankers.

Now, following the Islamabad negotiations, the world must gird itself for a game of bluff between Trump and Iran over which side will dare to try to stop the other from policing the strait. Trump’s declaration that US warships are now going to blockade the strait and prevent tolls being levied amounts to a dare to Iran to try to stop them. It is a bold gambit but also one that risks the war escalating once again.

Beyond that immediate question, the need for diversification of routes and  materials to make potential chokepoints less powerful is an obvious conclusion to be drawn from the Hormuz crisis, as is the need for investment in larger strategic reserves of key commodities. Taiwan must surely now realize that its still-small strategic energy reserves and other stockpiles make it highly vulnerable to a Chinese blockade.

Many of the other possible consequences will depend on what happens next in this war. But we can already see a fifth theme: that Donald Trump easily gets angry at any failure of America’s allies to support him, even though he has spent much of the past year insulting and abusing them.

The Iran war has already increased the chances that Trump may withdraw from NATO in a tantrum. There is no current danger of him breaking away from America’s Indo-Pacific alliances, but this war has confirmed that power in America is now highly concentrated in the hands of just one man, the president. He should, according to the US constitution, be gone in less than three years’ time, but he can make a lot of very personal decisions in the meantime.

He is not “our” president, but no-one can escape from the consequences of what he does.

This is a slightly updated version of an article first published by Mainichi. Along with many other articles it can be found on the author’s Substack, Bill Emmott’s Global View.