n his three years in office, U.S. President Donald Trump has aimed his trademark vitriol at a wide range of targets, both foreign and domestic. Perhaps the most consequential of these is the United States’ 70-year-old alliance system. The 45th president has balked at upholding the country’s NATO commitments, demanded massive increases in defense spending from such long-standing allies as Japan and South Korea, and suggested that underpaying allies should be left to fight their own wars with shared adversaries. Trump’s ire has been so relentless and damaging that U.S. allies in Asia and Europe now question the United States’ ability to restore itself as a credible security guarantor, even after a different president is in the White House.
But the tattered state of the alliance system is not Trump’s doing alone. After decades of triumph, the United States’ alliances have become victims of their own steady success and are now in peril. In the early years of the Cold War, the United States created the alliance system to establish and preserve the balance of power in Asia and Europe. To adapt the phrase of the commentator Walter Lippmann, alliances became the shields of the republic. These pacts and partnerships preserved an uneasy peace among the major industrialized countries until the end of the twentieth century. And they came with far fewer financial and political costs than Trump and some international relations scholars have claimed. When the Soviet Union collapsed, American policymakers wisely preserved this trusty tool of statecraft. But because the United States had no real peer competitors, the alliance system was repurposed for a world of American primacy and lost its focus on defense and deterrence.
Nearly 30 years later, an undeniably powerful China and a revanchist Russia have developed military and nonmilitary strategies that seek to unravel the system entirely. Trump’s antagonistic instincts are certainly destructive, but the changing nature of conflict is the true hazard. Faced with cyberattacks, disinformation campaigns, economic coercion, and more, Washington needs its alliance system to preserve order. If the pacts are to be saved, however, they must be renovated for the world they confront: one in which most threats to security and prosperity pass just below the military threshold