LONDON – Alone again. Since World War II’s end, Europe has looked at the world through a transatlantic lens.

There have been ups and downs in the alliance with the United States, but it was a family relationship built on a sense that we would be there for each other in a crisis and that we are fundamentally like-minded.

Donald Trump’s election as US president threatens to bring this to an end – at least for now. He believes more in walls and oceans than solidarity with allies, and has made it clear that he will put America not just first, but second and third as well. "We will no longer surrender this country, or its people,” he declared in his one major foreign-policy speech, "to the false song of globalism.”

Europeans will not only have to get used to Trump; they will have to look at the world through different eyes. There are four reasons to expect that Trump’s America will be the single biggest source of global disorder.

First, American guarantees are no longer reliable. Trump has questioned whether he would defend Eastern European NATO members if they do not do more to defend themselves. He has said that Saudi Arabia should pay for American security. He has encouraged Japan and South Korea to obtain nuclear weapons. In Europe, the Middle East, and Asia, Trump has made it clear that America will no longer play the role of policeman; instead, it will be a private security company open for hire.

Second, global institutions will come under attack. Trump fundamentally rejects the view that the liberal world order that the US built after WWII (and expanded after the Cold War) is the cheapest way of defending American values and interests.

Like George W. Bush after September 11, 2001, he views global institutions as placing intolerable constraints on US freedom of action. He has a revisionist agenda for almost all of these bodies, from the World Trade Organization to NATO and the United Nations. The fact that he wants to put the "Art of the Deal” into practice in all international relationships – renegotiating the terms of every agreement – is likely to provoke a similar backlash among America’s partners.

Third, Trump will turn all US relationships on their head. The crude fear is that he will be kinder to America’s foes than to its allies. Most challenging for Europeans is his admiration for Russian President Vladimir Putin. Should Trump, cozying up to Putin in search of a grand bargain, recognize Russia’s 2014 annexation of Crimea, the EU would be placed in a near-impossible role.

Fourth, there is Trump’s unpredictability. Even during the 18 months of the presidential campaign, Trump has been on both sides of almost every issue. The fact that he will say the opposite today of what he said yesterday, without admitting that he has changed his mind, shows the extent to which capriciousness is his method.

One of the benefits the US political system is that it provides a two-month grace period to prepare for Trump’s world. So what should Europeans do about it?First, we need to try to increase leverage over the US. We know from Trump’s writings and behavior that he is likely to resemble other strongmen presidents and treat weakness as an invitation to aggression. We saw from the Iraq experience that a divided Europe has little ability to influence the US. But where Europe has worked together – on privacy, competition policy, and taxation – it has dealt with the US from a position of strength.

The same was true with the so-called E3+3 policy on Iran – when the big EU member states shifted the US stance by standing together. To get on the front foot, the EU now needs to launch a process to agree on common policies on security, foreign policy, migration, and the economy. This will be difficult, as Europe is deeply divided, with France fearing terrorism, Poland dreading Russia, Germany inflamed by the refugee issue, and the United Kingdom determined to go it alone.

Second, Europeans should show that they are able to hedge their bets and build alliances with others. The EU must reach out to other powers to help shore up global institutions against Trumpian revisionism. And it also needs to diversify its foreign-policy relationships. Rather than waiting for Trump to marginalize the EU over Russia and China, Europeans should fly some kites of their own. Should they, for example, begin consulting with the Chinese on the EU arms embargo to remind the US of the value of the transatlantic alliance? Could the EU develop a different relationship with Japan? And if Trump wants to cozy up to Russia, maybe he should take over the Normandy process on Ukraine?

Third, Europeans need to start to invest in their own security. From Ukraine to Syria, from cyber attacks to terror attacks, Europe’s security is being probed in different ways. Despite an intellectual understanding that 500 million Europeans can no longer contract out their security to 300 million Americans, the EU has done little to close the gap between its security needs and its capabilities. It is time to put meat on the bones of the Franco-German plan for European defense. And it will be important to find institutionalized ways of binding the UK into Europe’s new security architecture.

In all of these areas, Europeans must keep the door to transatlantic cooperation open. This alliance – which has so often saved Europe from itself – is bigger than any individual. And, in any case, Trump will not last forever. But the transatlantic relationship will be more likely to survive if it is built on two pillars that understand and defend their own interests.

This will be a tough agenda to adopt – not least because Europe is facing its own brand of populist nationalism. France’s far-right National Front leader, Marine Le Pen, was among the first to congratulate Trump on his victory, and Trump has said that he would put the UK at the front of the queue after Brexit. But even Europe’s most Trump-like leaders will find it harder to defend their national interest if they try to go it alone. To survive in Trump’s world, they should try to make Europe great again.

The writer is Director of the European Council on Foreign Relations.

Copyright: Project Syndicate