The next two weeks are potentially decisive for US relations with Europe and especially NATO. As The Washington Post argues, there could be a “catastrophe.” NATO leaders meet in Brussels on July 11-12 and then President Donald Trump meets with Russia’s president Vladimir Putin in Helsinki on July 16. Most commentators see the two events as inextricably linked. In Brussels, they expect Trump to undercut the alliance and demonstrate that the United States is not wholeheartedly committed to it, while they worry that in Helsinki he will sell out the West for the equivalent of a mess of pottage to the master of the Kremlin.

This is a potent narrative. But it depends on the validity of several assumptions, most important being that Trump is totally unaware of US interests in Europe and the world in general, doesn’t care, or is so besotted with Putin as to come perilously close to committing treason.

According to other prevailing assumptions, there is already a new Cold War with Russia and that Putin alone is responsible for it, while the US has totally clean hands. Also, Russia’s aggression in seizing Crimea and its military actions in other parts of Ukraine require a substantial NATO military buildup, without which Putin is highly likely to push Russian military forces further westward, including into the Baltic states (formal NATO allies) and perhaps also northern European neutrals (Finland and Sweden). A final assumption is that, even absent direct Russian military pressures, the buildup of NATO military forces is both necessary and sufficient to deter other threats that Russia poses, as in cyber-attacks and interfering in Western politics, societies, and democratic practice in general.

The 2% Solution

It follows from these assumptions that all NATO members should increase defense spending to at least 2% of GDP, a NATO-agreed goal to be achieved within the next eight years. Secretary of Defense Robert Gates pulled this figure out of the air in 2011 and made a challenge to the allies as he was leaving the Obama administration. This was years before Russia seized Crimea. The 2% goal has subsequently become the standard for judging whether allies are pulling their weight—even though meeting such spending levels would not in itself translate into useable military capabilities. It also ignores other essential aspects of providing security. In terms of countering potential threats to the security of several countries in Central Europe, including Ukraine, Western investments in economic, political, and social development could be of equal or even greater importance.

Further, the solidity of Western security and allied cohesion are today threated less by Moscow than by anti-democratic actions in at least two NATO allies, Poland and Hungary, as well as some disturbing political developments in Romania, Italy, Austria, and even at the fringes in Germany. Stresses faced by the European Union, in major part because of the flow of refugees from the Middle East produced largely by the US-led invasion of Iraq in 2003, are also major threats to European security and directly benefit Putin. On the European migrant problem, the United States has been of zero help under both the Obama and Trump administrations.

Trump fully supports the concept that the European allies need to increase defense spending to the 2% of GDP goal. He believes that many of them are effectively getting a free ride, want the US to take their security more seriously than they do themselves, and are taking advantage of the US in defense as well as in trade.

However, the security perspectives of almost all the European NATO allies, save Britain and France, are focused on the continent, with only minor commitments elsewhere such as in Afghanistan and countering what is left of the Islamic State. By contrast, the United States has worldwide commitments and engagements—for which it devotes about 3.5% of GDP to the military—and only deploys a small fraction of its forces in Europe. Even in a major conflict with Russia, the US would engage in Europe only part of its military power, which would represent well below the 2% NATO target. Of course, US military power is huge, and even 1% of GDP would make it the most potent force in Europe. But the point about lecturing the allies in GDP terms is instructive.

“America First” and American Responsibilities

The foregoing is not intended to rationalize Trump’s meat-axe approach to decades of US leadership in creating, maintaining, nurturing, and developing the international system of relations among states. It is not to deny the value of increasing NATO military capabilities, both as a prophylactic and to foster a greater sense of psychological confidence in countries close to Russia. And It is not to sugarcoat Trump’s gross failure to understand that US power and influence in the world, essential underpinnings of his desire to put “American first,” demand that the United States also work effectively with other countries, especially its allies and partners around the world. Pearl Harbor ended US isolation, while 9/11 ended for all time America’s insulation. It’s too late to do anything about those facts.

Backing away from US global responsibilities, shared with other countries, would require not just that Trump use the powers conferred on the presidency. It would also have to be fully backed by Congress and the US private and non-governmental sectors across the board. In the unimaginable event that such support would be forthcoming, Trump would bring down America’s whole economic, social, and national security house of cards. Being engaged in the outside world and working with others according to widely agreed rules of the road, even if they need reforming, is not a choice. Some rules are a requirement mandated by the facts of global economics and the irreducible needs of individual countries and societies, including the United States.

Trump can no more change those facts than he could repeal the law of gravity.

The Bottom-Line Need

President Trump should go to the NATO summit in Brussels and behave himself, avoid insulting other allied leaders, and not make threats about reducing US engagement in Europe if allies don’t increase defense spending and meet Trump’s trade demands. His good behavior—though hopes in this quarter died long ago—would also help reassure allies before Trump meets with Putin that he will not fall for the Russian leader’s blandishments or agree to any grand bargains, perhaps in the Middle East, that would be hostile to core Western interests. And it could help promote acceptance of Trump’s accurate assertion that the United States and the West must deal with reemergent Russia—despite the prevailing narrative that Trump is Putin’s lapdog, which the mainstream media use to try driving Trump from office.

There is only one irreducible requirement for Trump at the NATO summit: he should not say or do anything to indicate that the United States is unwilling to honor Article 5 of the NATO Treaty, that “an armed attack against one or more of [the allies]in Europe or North America shall be considered an attack against them all.” This commitment, which has force and validity only if the United States fully embraces it, is the core of the alliance and the most important method of forestalling Russian military aggression against any NATO ally or other countries in Europe, if indeed Putin has any such intention. Only Trump’s ratifying this US commitment will get the Russian leader’s full attention and reduce any belief Putin may have that he can manipulate Trump to betray Western interests. Of course, deploying NATO forces in Central Europe and making other preparations for possible conflict are also useful for reassuring allies of the indispensable American commitment, but they essentially serve as a tripwire and are ancillary to US fealty to Article 5.

Reducing the requirement for Trump’s performance at the NATO summit to a reaffirmation of this one element, while trying to ignore how badly he behaves towards allied leaders, is a form of triage. At Brussels, that means trying to minimize uncertainties generated by Trump’s untamed rhetoric and quixotic behavior. Since the United States is asking them to do more, the allies also reasonably want more from across the Atlantic, notably classical American alliance leadership. This is especially valued now, given their own deep internal divisions, which are magnified by the rot in democratic practice in some countries and the damage being done to security and the future of the European Union and Western security caused by Brexit.

But the one key requirement for Trump at Brussels—full-throated adherence to Article 5—is about the best we can hope for.