Former President Trump inflicted a variety of misfortunes on the United States in his interminable four years in office, none more catastrophic than his inept handling of the ongoing COVID-19 pandemic. But one area where he escaped serious disaster was in the realm of foreign policy, where the only real crises he faced were mostly of his own making, like his terrifying will-they-or-won't-they Twitter spats with North Korea's Kim Jong Un.

As President Biden seeks to pilot the country out of the morass of its long virus nightmare, it appears that this luck might be running out. A number of global hotspots are getting hotter, and they are uncomfortably exposing some unrealities and contradictions at the heart of America's fraying foreign policy consensus.

The most concerning of these growing threats is in Eastern Europe, where Russia is massing tens of thousands of troops on the border with Ukraine, threatening to add more territory in the country's restive Eastern provinces to Vladimir Putin's brazen annexation of the Crimean peninsula in 2014. Ukrainian President Volodymyr Zelensky is begging the U.S. for reinforcements, and Biden reportedly proposed a summit with Putin to address the build-up. With many of the world's most powerful countries still wracked by rising COVID case loads and vaccine administration challenges, Putin might just calculate that now is the perfect time to move.

To Ukraine's southeast lies the unresolved conflict over Iran's nuclear program. Even as U.S. and Iranian negotiators meet in Vienna in a last-ditch effort to reassemble the Joint Comprehensive Plan of Action after years of pointless and malignant sabotage by the Trump administration, an Israeli cyberattack on the Iranian nuclear facility in Natanz threatens to derail those diplomatic efforts and bring the U.S. and Iran once again to the brink of an armed conflict that no one wants but which no one can seem to permanently take off the table.

There is also heightened concern about simmering tensions between mainland China and Taiwan, which Beijing considers a breakaway province, and whose territorial integrity is informally guaranteed by the United States. China has recently begun conducting substantial incursions into airspace claimed by Taipei, while disturbingly bellicose rhetoric emanates out of Beijing. Recent U.S. military war games around a Chinese invasion of Taiwan have been "sobering," according to observers, sparking fears that the U.S. no longer possesses the qualitative military edge over China that allowed Washington to rule the Pacific for decades.

None of these issues is necessarily destined to spiral immediately into armed conflict. But President Biden may be forced to answer some uncomfortable questions that have hung over U.S. foreign policy for decades. What exactly are the U.S. and its allies willing to do to halt Putin's creeping reclamation of areas with large Russian-speaking populations who were left outside of the frontiers of the Russian federation when the Soviet Union collapsed 30 years ago? American foreign policymakers consistently refer to Ukraine as an ally, but it is outside the NATO mutual defense framework, as is Georgia, where Russia intervened to assist separatists in 2008. Both countries are now fragmented, with little hope of restoring their pre-existing frontiers. Russia has also supported separatists in Transnistria (ostensibly part of Moldova) and their effort to erect a quasi-autonomous satellite state.

Thus far, Russia has paid little to no price for these efforts, rendering hollow any subsequent red lines delineated by U.S. policymakers. With significant Russian-speaking populations located all over the former Soviet Union, the potential for further conflict and unilateral border revisions is substantial. Will Americans be willing to die for Kiev or Tbilisi?

The same dilemma awaits the United States elsewhere. The question is not whether the continued existence of a free and democratic Taiwan or a non-nuclear Iran is preferable — of course it is — but rather what the United States is willing to risk and to sacrifice to make it so.

The causes of these emerging foreign policy binds are simple. For many years, unrivaled American power has been a substitute for clear thinking about the relationship between means and ends. And while the U.S. is still the world's predominant military power, it lacks the kind of easy supremacy it possessed in the two decades following the end of the Cold War. Yet, despite Biden announcing a much-belated withdrawal from Afghanistan, America's overseas commitments remain just as expansive as they were during what scholars call the "unipolar" era, when the United States was the world's unquestioned economic and military hegemon.

Successive U.S. policymakers during this period did themselves no favors when they squandered untold trillions in irreplaceable material and soft power resources in a quixotic attempt to garrison the Middle East and then to prosecute an unwinnable "Global War on Terrorism." Both endeavors went disastrously sideways. The Persian Gulf is now ringed with dangerously failed and failing states, and U.S. meddling exacerbated uncontrolled tensions between Iran and Saudi Arabia when what was really needed was careful diplomacy. All of this transpired while China was dramatically improving its military and economic position, and while Russia was rousing itself out of its post-Cold War stupor, preparing to take revenge for what it now regards as an unfavorable territorial settlement that was imposed by the West at Russia's weakest moment.

To make matters worse, 21st-century Republican presidents George W. Bush and Donald Trump gleefully dismantled the institutional bases of the post-WWII global order — Bush by torpedoing the International Criminal Court, undermining climate change efforts, and making a mockery of the U.N.'s role in preventing armed conflict; and Trump by cheerleading Brexit, assailing NATO allies, and then pulling the U.S. out of the Iran Deal, the Paris climate accords and even the World Health Organization. None of these institutions were perfect, but collectively they served as a kind of non-military arm of international liberalism. Without them, and without the ideological consensus they served, the task of maintaining order and stability has become far more challenging.

The U.S. could have spent the years of its relative decline enlisting support from allies and friends around the world to contain the influence of China and to reinforce the redoubts of liberalism against the coming assaults from Beijing and Moscow. Instead, at nearly every critical juncture the U.S. made what seem to be the most destructive decisions possible. Led by people intoxicated by the fumes of unlimited power and in the grips of a delusion that its temporary position atop global hierarchy would continue indefinitely, America's leadership class failed comprehensively to chart a realistic path into the multi-polar world that everyone else has known was coming for years.

For roughly 20 years after the collapse of the Soviet Union, America never really had to choose between things it wanted to happen and things it could make happen with its power. The two were largely one and the same, or at least policymakers thought they were. But today the twin pillars of America's post-WWII foreign policy philosophy — the spread of democracy and economic integration abroad — are crumbling. Democracy is in rapid retreat in the U.S., and Washington's chief international competitor is a brutal, unforgiving autocracy which has only grown more illiberal and aggressive over time, rather than turning gradually into a democracy, as the architects of engagement hoped.

Now here we are, with America's irrational attempts to control the Middle East, its shaky commitment to Taiwan, and its hollow promises to non-NATO states on the Russian periphery all coming to a head at the same time. Trump rightly perceived the lack of fit between U.S. global ambitions and its relative power, but failed to formulate, let alone implement, a coherent plan to right-size our foreign policy.

It's just one more urgent task he dropped into the lap of Joe Biden. Let's hope he's up for it.