To much of the foreign policy community, Les was like Elvis—instantly identifiable by his first name. Mentor, friend, (constructive) critic, (occasional) pain in the posterior, he pushed so many of us to be the best version of ourselves—to think more boldly and act more strategically. We miss his sharp wit but genuine warmth, and the manner in which he always delivered his advice with true affection, though without pulling his punches. And we miss being part of the honorary extended family he created, as he prized his commitment to family above all else. Les enveloped us in the belief that we could make a difference and gave us the tools to do just that.

Yet Les would not have been as storied a mentor if he was not also typically right on the substance—both in diagnosing the problem and in prescribing a solution. His prescience is particularly noteworthy in his final chapter of Power Rules—“Necessity, Choice, and Common Sense.” Years before the rise of Trumpism, he foresaw this consequential inflection point in American democracy—and gave us a roadmap with which to navigate its dangers. On the cusp of the 2020 elections, he provides clear guidance on this last, best opportunity for America to resuscitate its role as a global leader in an increasingly fractured and rudderless world.

Les understood that the world does not organize itself. If the United States does not play a lead role in setting the rules, shaping the norms, and animating the institutions that govern relations among nations, then one of two things occurs. Either some other country or countries fills that void—and likely not in a way that advances our interests and values—or no one will and the law of the jungle will prevail. Either way, the result is bad for America.

While Les wrote sorrowfully of the United States as a declining power, a decade later we are accelerating that decline by retreating from the global stage, undermining the liberal international order that we helped to establish. As was Les’s hallmark, his proposed solution was direct, down to earth, and accessible—it was based on the premise that “foreign policy is commonsense, not rocket science.” He identified the obstacles to a “commonsense foreign policy” as nasty politics, extravagant principles, and the arrogance of power—all of which have only escalated in the past decade. His antidote was to confront the reality of America’s declining power and be modest and realistic about what’s achievable.

Today, his plea for grounding foreign policy in common sense is more resonant than ever. At a moment when there should be a premium on cooperation to meet challenges that no one nation can address alone, how is it commonsensical to turn on our most stalwart allies and undercut multilateral institutions, whose necessity is greater than their imperfections? Or to deny science and withdraw from global efforts to address worldwide concerns, from the environment to health risks to proliferation, without proposing any alternatives in their stead? Or to cozy up to dictators and autocrats while showing disdain to democrats? By contrast, a commonsense policy would value partnering over bullying to leverage America’s unique ability to rally the global community in addressing our most intractable common problems.

Les also presciently identified trends that have become even more pronounced since he wrote of them—especially that an effective foreign policy requires that we first address our core domestic concerns. This includes our massive federal debt (over twice as large now than at his writing), our deteriorating public schools, our decaying infrastructure, our declining investments in our people, and our dysfunctional political system, now on the verge of a constitutional crisis. In short, we must first heal ourselves before we can once again become a credible beacon to others.

In Les’s inimitable manner, he would never identify a problem without also offering a pragmatic guide to resolving it. His prescription for revitalizing U.S. power was dependent on remaining “clear-eyed about the causes” and “courageous about implementing the cures.” His criteria for a commonsense foreign policy are the underlying tenets for any post-Trump administration, including prioritizing economic dynamism, recognizing our mutual indispensability with our partners, addressing our greatest threats first, investing pre-emptively, and recognizing that power isn’t what it used to be. Les also offers a prescient ode to moderation at a moment when extremism appears more unleashed than ever before. Long before this MAGA moment, Les asked how we could wean America from extremist tendencies, and that threshold inquiry has grown even more urgent given the rise of disinformation in our technology and media.

America’s global leadership has not yet been replaced, as others have not yet filled the destabilizing vacuum created by our (hopefully temporary) absence. But time is short to revive our global role. Equally important is to recognize that a new era of American leadership would likely be distinct from the role we have played to date in the post-War era. Power shifts among and beyond nations have profoundly reshaped the landscape. New actors—empowered by technology and the unbridled flow of information—have a greater ability than ever before to veto the outcomes we seek.

And President Trump’s wholesale assault on American exceptionalism—his incessant attacks on our institutions, his adversarial relationship with the truth, his disdain for democratic principles, his embrace of conspiracy theories—has done real damage to our place in the world. Gone are the days when we could launch multilateral agencies with a disproportionate percentage of control, or speak credibly about core freedoms of the press or rule of law—given that those very principles are undermined daily by our own President. A post-Trump global leadership role for the United States will by necessity take a more sober, honest, and humble form, as it would be shaped by our newly acquired first-hand knowledge of the fragility of democratic institutions, even in the most mature of democracies.

As we confront this critically important opportunity to stabilize and ultimately safeguard our democratic experiment, we miss Les’s visionary role in serving as a steward, but remain inspired by the closing sentiment of Power Rules—that we Americans “are worth fighting for,” as the United States “remains the last best chance to create equal opportunity, hope, and freedom.”