Witnessing events in Europe over the past few months, it can seem as though the clock has been turned back and history is picking up again from 1945: troops and tanks on the move, ruined cities, civilian suffering. In this new alternate version of history, one vanquished nation, Germany, has exchanged a broadly pacifistic stance for a hardening of its foreign policy and a dramatic ramping up of military spending. Another, Japan, may soon follow suit.

In the decades after 1945, Japan and (West) Germany took somewhat parallel paths. A period of Allied occupation involved the convening of war crimes trials — in Nuremberg and Tokyo — as part of a broader, concerted Allied effort via education and the mass media to instil in the defeated populations a love of liberal democracy and a deep aversion to militarism.

They met little resistance. The profound shock of being led into wars that ended up costing tens of millions of lives — including those of millions of Japanese and German civilians — was by itself sufficient to generate amongst the two countries’ intellectuals, political leaders and people a powerful desire for a new purpose as champions of pacifism and international co-operation. Opposition to nuclear weapons was an important component, Japan having suffered the world’s first atomic attacks at Hiroshima and Nagasaki, and both countries fearing Soviet nuclear missile strikes should war break out between the US and the USSR.

Still, in the early years of the Cold War, both Japan and West Germany were home to fierce debates about rearmament. West Germany’s constitution, the ‘Basic Law’ of 1949, contained no provision for the reinstatement of armed forces. Japan’s postwar constitution (1947), authored by American occupation personnel, outright forbade both the settling of international disputes by military means and the maintaining of armed forces and other war potential. (The presence of American military bases on Japanese soil was briefly contested in the courts on this basis, ultimately unsuccessfully: US bases remain in Japan to this day, particularly in Okinawa). But souring Western relations with the USSR, along with China’s Communist Revolution in 1949, helped to turn the tide against early postwar idealism. In 1950, shortly after the outbreak of the Korean War and under intense American pressure, the Japanese government established a heavily armed ‘National Police Reserve.’ It was reconstituted as the ‘Self-Defence Forces’ in 1954. The next year, in 1955, West Germany’s Basic Law was amended to allow for the creation of a federal armed forces: the ‘Bundeswehr’ (‘Federal Defence’).

Great efforts were made to win round sceptical domestic populations. The Bundeswehr was organised along strictly defensive and democratic lines, reporting directly to the Minister of Defence. Its independent planning capabilities were kept deliberately under-developed, the intention being to rely for such things on NATO, which West Germany joined in 1955 just days after the American, French and British occupation officially ended. The image of the Self-Defence Forces (SDF) was meanwhile carefully managed at key moments, such as the Tokyo Olympics in 1964. SDF personnel helped to manage security at the opening ceremony while their acrobatics display team, Blue Impulse, traced the Olympic rings in the sky above.

There was work to do, too, in building up trust abroad. Misgivings in France about West German rearmament ran alongside concern in East Asia about a possible return by Japan to its old colonial and militarist ways — abetted, this time, by the United States. Some of that concern had to do with resentment amongst Japan’s former enemies and colonies in Asia that defeat and punishment in 1945 had turned so swiftly and vividly into enviable prosperity. And yet there was a sense, too, that Japan had yet to match West Germany in reflecting on its earlier war-making and seeking to make amends amongst its neighbours.

Where and how these two institutions, the Bundeswehr and the Self-Defence Forces, ought to be allowed to operate became the subject of fierce debate in Germany and Japan after the end of the Cold War. Pacifism remained a powerful current in the politics of the two nations, partly on historical and moral grounds and partly because it had proven so good for business: both countries managed to rebuild and prosper while having their security underwritten by the United States and its allies. For both Germany and Japan, trade and investment rather than military might had become central to how they projected their influence around the world. On the other hand, long before Russia’s invasion of Ukraine in 2022, both countries were coming under pressure to strengthen their foreign policy and boost their military commitments.

Russia’s annexation of Crimea in 2014, and NATO’s guidance the same year that member states should spend two per cent of GDP on defence, contributed to a gradual re-thinking of policy in Germany that culminated in Chancellor Scholz’s Zeitenwende (‘historic turning point’) speech just three days after Russia’s invasion of Ukraine in late February 2022. Japan, meanwhile, had seen a long-running debate about whether Article 9 of its constitution, the so-called ‘pacifist clause’, ought to be revised in light of changing circumstances in the world, from what seemed to some to be a waning American commitment to Japan’s security to the rise of China as an economic and military superpower.

An important part of the popularity of Scholz’s Zeitenwende in Germany has been a deepening realisation amongst ordinary Germans that the old approach of ‘Wandel durch Handel’ [‘change through trade’], that is, using business links to repair or maintain relations with potentially hostile powers — has distinct limits. If China’s seemingly decisive move away from democracy under Xi Jinping was suggestive of this, Russia’s invasion of Ukraine — and the failure, so far at least, of sanctions to persuade Vladimir Putin to change course — made the point viscerally and unmistakeably. There are now strong majorities in Germany both for aiding Ukraine and for reducing economic dependency on Russia.

If the Ukraine crisis is concerning Germans, heightening a centuries-old preoccupation with its powerful near-neighbour Russia, it is potentially far more worrying for Japan. The country’s approach to Russia in recent years had been remarkably similar to Germany’s: seeking to maintain economic ties and to keep criticism of Putin to a minimum. The aim, in Japan’s case, was the successful conclusion of years of negotiations with Russia over four small islands to the north-east of Hokkaido, known collectively as the Kurils and seized by Soviet troops towards the end of the Second World War. Japan and Russia have yet to even agree a peace treaty to end that conflict, nearly 80 years on.

But negotiations over the Kurils were terminated by Moscow in March 2022, in response to Japanese sanctions on Russia following Putin’s attack on Ukraine. The weeks since have seen further deterioration in relations between the two countries. Japan has joined its allies in freezing Russian assets and restricting trade and banking transactions. It has pledged hundreds of millions of pounds in support for Ukraine, and agreed to increase military co-operation with NATO. Russia, meanwhile, has hit back with measures including the suspension of permits allowing Japanese fishermen to operate near the Kurils.

If relations with Russia have become notably more tense, the real worry for Japanese policymakers — and the greatest pressure on the country’s postwar pacifism — is China.

Chinese officials watching the Ukraine crisis play out will be learning a number of useful lessons. Amongst them is the need to invest well ahead of time in the ability to withstand a prolonged period of trade and banking sanctions. Officials in Beijing will also be taking note of the number of countries around the world, including India, which appear open to prioritising economic self-interest over joining boycotts on an aggressor.

Nor will it escape notice in China that Putin’s threat of heavy retaliation for interference in what he regards as his affairs, which included a hint at deploying nuclear weapons, has succeeded, to an extent, in muting Western responses to the crisis. Ukraine’s President Zelensky is finding that he does not get all the firepower he asks for, while Western resolve — amidst rising prices and the prospect of a long war — shows signs of faltering. Some in the West appear to be banking on opposition to Putin building up in Russia, as casualties mount. But that has yet to materialise.

All of this will likely factor into Chinese calculations when it comes to their planning for an attempt to take Taiwan by force, widely expected within the next decade. The specialist military means to make such an attempt (maritime and airborne forces capable of rapidly crossing a small stretch of water) are the same ones required to settle territorial disputes with Japan, over the disputed Senkaku/Diaoyu islands for example, by force.

There are strong arguments here for those in Japan who seek an expanded SDF. The Ukraine crisis has torpedoed relations with Russia and emboldened China, in an era when American commitment to Japan seems more than ever to depend on domestic politics in the US. Where President Trump appeared to regard the US-Japan security relationship as an outrageous freebie, an unreciprocated US pledge to defend Japan if attacked, President Biden has rolled back some of the traditional ambiguity about his country’s willingness to come to Taiwan’s defence. The next US election could well have very serious consequences for Japan.

The worst-case scenario, which successive Japanese leaders have sought to keep at bay, meanwhile seems to have been brought closer by the crisis in Ukraine: an alliance between Russia and China. Xi Jinping has held off, in public at least, from criticising Putin’s war or suggesting that he step back. He surely finds it easy to see things from Putin’s point of view: an authoritarian leader, in power for many years, risking his reputation over the invasion of a near-neighbour. Still, it will have come as a shock in Japan when in May of this year China and Russia launched a joint nuclear bomber exercise not far from its territory.

The nature of deterrence in East and South-East Asia, foreign policy hawks in Japan say, must now change. As a non-NATO member, and one whose geographical position means it is not easily reached by friends willing to supply weapons and ammunition in an emergency, Japan should strengthen its own military ties in the region while ensuring that its military capabilities alone would be enough to deter China from aggressive action against it. Moves in this direction may come later this year, when Japan revises its National Security Strategy for the first time since 2013.

The Japanese public, however, have yet to show themselves enthusiastic about a dramatic change of course. Some of the original pacifist generation, of the 1950s and 1960s, are still around and there is little sign of a younger generation taking a radically different view. Sanctions against Russia are popular. So, by a smaller margin is the idea of spending more on the Self-Defence Forces, with threats from Russia, China and also North Korea in mind. But revision of Article 9 remains unpopular by a slight majority; there remains little appetite for stationing nuclear weapons on Japanese soil; and the population appears split on the question of whether the SDF should be permitted a first-strike capability (striking an enemy base if there is evidence that an attack on Japan is being prepared there). For critics, such a change in policy raises the spectre of a Japanese attack, launched on the basis of poor intelligence or political judgment, actually sparking a conflict that would otherwise not have happened. Japan meanwhile retains strong trade ties with China, and within living memory relations between the two countries have soured, notably in the early and mid-2010s, only to recover again.

Besides, there is one lesson from the Ukraine crisis that may play in Japan’s favour. Most analysts agree that Putin’s war is going much less well than he might reasonably have expected. For all the money being thrown by China at the People’s Liberation Army, it is largely untested in battle. Would it necessarily fare any better than the Russian armed forces — in what would be a far more complex undertaking than Russia rolling into Ukraine? By the time that a Chinese invasion of Taiwan becomes logistically feasible (2027 at the earliest, it is thought) the lessons from Ukraine may look rather daunting for Xi: a partial annexation that proves bloody and unprofitable for the occupiers; Putin’s hold on power weakened, and possibly lost; Russia’s reputation and economic strength struggling to recover.

It is too early to know just yet whether the alternative post-1945 history for Germany and Japan set in motion this year might take the two countries. But it seems likely that much will depend on the resolve shown across coming months by Putin’s opponents. The common refrain so far has been that ‘Putin cannot be seen to win this war.’ That may turn out to matter a great deal not just for Ukraine, but for the future of the German and Japanese populations too.