Mark Twain is often quoted as saying, ‘History may not repeat itself, but it often rhymes.’ He might have added that when history does rhyme, the results are often disastrous. 

Just as the territorial ambitions of the Axis powers—Germany, Italy, and Japan—set the stage for World War II, the current authoritarian bloc of China, Russia, Iran, and North Korea seeks to dismantle the liberal international order. Now, as then, various conflicts around the world could spiral into a worldwide war. 

Consider, for example, the very real possibility that former US President Donald Trump will return to the White House in 2025. Given his blithe disregard for Europe’s security, it is clear why European countries, which have relied on the United States for their security since the end of World War II, should be concerned. 

But this is not just about Trump. Given China’s growing influence and the subsequent rebalancing of US strategic priorities, even a second Joe Biden term could lead to a reduced American commitment to NATO in favor of AUKUS, the military partnership that he created with Australia and Britain to face China’s threat in the Indo-Pacific. America’s waning interest in Ukraine underscores this shift, with Europe left to fill the resulting security vacuum.  

Consequently, fears of an imminent war have seized European capitals. Polish Prime Minister Donald Tusk recently said that Europe had entered a “pre-war era,” while European Commission President Ursula von der Leyen warned that a land war on the continent “may not be imminent, but it is not impossible.” Meanwhile, French President Emmanuel Macron has not ruled out the possibility of sending troops to Ukraine, and the United Kingdom’s Chief of General Staff, General Patrick Sanders, has called for ‘national mobilization’ and said British citizens must be ready to fight Russia.  

While Russia represents a distant threat to countries like Spain and Italy, most EU member states fear that Russian President Vladimir Putin is on their doorstep, highlighting Europe’s lack of strategic autonomy. McKinsey estimates that European countries saved $8.6 trillion over the past few decades, compared to average defense spending from 1960 to 1992, by downsizing their militaries. Mainly deployed in humanitarian and peacekeeping missions, European military forces have been described as ‘bonsai armies’—miniature versions of real armies, with limited combat experience. 

Moreover, given that Europe’s defense industry lags far behind Russia’s, and even more so the US’s, building up Europe’s military capabilities will probably take years. Tellingly, the entire ammunition stockpile of the German armed forces would sustain just two days of combat against an adversary like Russia. 

While Russia is not as strong as it once was, Europe has good reasons to be concerned. Putin’s determination to reverse the outcome of the Cold War has escalated into a near-religious obsession with restoring Russian imperial power. His war of aggression in Georgia in 2008, annexation of Crimea in 2014 and full-scale invasion of Ukraine in 2022 illustrate his relentless ambition. Under Putin, Russia’s ships and spy planes regularly survey the borders of countries like Sweden, Finland, the Baltic states, and even Britain. 

Putin’s aggression has forced Europe to abandon its post-historical mindset and get serious about rearmament. Military spending by the European Union’s member states reached a record of €240 billion ($260 billion) in 2022, 6 percent more than in the previous year, with McKinsey projecting that Europe’s annual defence expenditures could increase to €500 billion by 2028. 

The organisational and material degradation that Russia’s military has suffered during two years of intense fighting in Ukraine, along with the risk that a full-scale mobilisation for war with NATO could destabilise his regime, will likely deter Putin from embarking on additional military campaigns in the foreseeable future. If Russia’s gains in Ukraine are limited to its current defensive lines without a decisive victory—an outcome contingent on Western support for Ukraine—Putin’s appetite for further adventures in the Baltics would be severely diminished. Nevertheless, this would not prevent him from trying to destabilise Moldova, Georgia, the South Caucasus, the Western Balkans, and even France and Britain, nor would it limit the operations of his private military forces in Africa. 

But Putin’s nuclear threats reflect Russia’s inability to compete with NATO in a conventional arms race of the kind that crippled the Soviet Union in the 1980s. Even though European countries still spend less on defense than the NATO target of 2 percent of GDP, Russia cannot match the combined defense budget of NATO’s member states, even without the US.  

But while higher military spending could deter Russia from attacking European countries, larger defence budgets alone will not solve the continent’s strategic problems. To defend itself, Europe must also improve the integration and interoperability of its various military cultures and weapon systems. Given that this will be a prolonged process, von der Leyen’s proposal to establish an EU Defense Commissioner is a step in the right direction. 

Europe also needs to reduce its reliance on the US nuclear umbrella. Establishing an independent European nuclear deterrent, which only France and Britain can provide, is crucial to countering Putin’s aggression. Without such a deterrent, as The Economist put it in February, the same rationale that led France to develop its nuclear deterrent force—the notion that America would not sacrifice New York for Paris—could now extend to the rest of Europe: Would France be willing to risk Toulouse for Tallinn? 

That said, even if Europe were to improve its deterrence capabilities, it would be unwise to assume that leaders necessarily make rational decisions. In her 1984 book The March of Folly, historian Barbara Tuchman observes that political leaders frequently act against their own interests. America’s disastrous wars in the Middle East, the Soviet Union’s ill-fated campaign in Afghanistan, and the ongoing war of blind hatred between Israel and Hamas in Gaza, with its potential to escalate into a larger regional conflict, are prime examples of such missteps. As Tuchman notes, the march of folly is never-ending. That is precisely why Europe must prepare itself for an era of heightened vigilance.