Are Donald Trump and his unconventional methods the death of U.S. grand strategy? Over at Foreign Affairs, Professors Daniel Drezner (Fletcher School, Tufts), Ronald Krebs (University of Minnesota), and Randall Schweller (Ohio State) reply in the affirmative. Why not break a lance with them to break the monotony on a gloomy pandemic spring day? Here’s my reply in the negative.

Without a doubt, President Trump brings a madcap style to foreign policy and strategy. And without a doubt, as the trio contend, his “disruptions have forced foreign policy analysts to question first principles for the first time in decades.” His approach brings to mind The Maltese Falcon, the novel (and film noir classic) in which author Dashiell Hammett has detective Sam Spade inform client and femme fatale Brigid O’Shaughnessy that “my way of learning is to heave a wild and unpredictable monkey-wrench into the machinery” and see what comes flying out. Like Hammett’s gumshoe, Trump flings monkey wrenches in the foreign-policy works all the time—gleefully, and probably out of conscious choice.

The United States need not discard first principles, but revisiting them from time to time is a healthy thing. Otherwise, principles ossify into dogma. And dogma has a way of slowing and misshaping adaptation when the times and circumstances change around a strategic actor, as they have around America over the past decade or so and will doubtless do so again.

Three major points. One, Drezner, Krebs, and Schweller overstate how much the strategic environment has changed. They lament how “entropic” the world is nowadays and despair of “predictable terrain” for making and executing strategy. Welcome to life in the arena. Entropy is the terrain when human wills collide and interact. Overseers and executors of policy and strategy inhabit a disorderly world, and always have. They must learn to thrive amid countless factors that deflect events from a linear, predictable pathway. Contestants try to impose their will on unwilling rivals and balk their strategies. Impassioned societies clash. Technology advances in fitful and oftentimes bewildering ways. Chance, surprise, and uncertainty lurk. And on and on.

World politics morphs in outward ways all the time. Its essential features endure from age to age. Donald Trump has not created some brave new world where time-tested methods no longer apply.

Two, while the Trump administration employs an unorthodox and admittedly disconcerting style, it’s noteworthy how little the administration has departed from the substance of precepts that have governed U.S. grand strategy for many decades. Strategic geography compels the United States to pursue a seaward-oriented grand strategy. That being the case, the tenets of U.S. maritime strategy have a way of remaining in force as presidents come and go, even though presidents may put those tenets into effect in different ways.

Let’s rewind and start with the basics. At its most fundamental, strategy is the art and science of devising ways to put power to work fulfilling national purposes. Ends, ways, and means, to recite the shorthand popular among defense specialists. English soldier B. H. Liddell Hart, the forefather of the concept of grand strategy, defines it as engineering “a better state of peace—even if only from your own point of view.” If at all possible a competitor should pursue lofty goals without resort to arms, and spare itself the hardships, costs, and perils of war. There’s a grand-strategic principle on which Americans surely agree, however much they may quarrel over what would improve the diplomatic, economic, and military surroundings and how to bring about such improvements.

Liddell Hart settles the trivial case by formulating a generic definition of grand strategy: making things better. He hands Washington a rough guide to how to undertake the “case-by-case” policymaking the coauthors espouse. It’s worth noting, incidentally, that peacetime strategy always takes place on a case-by-case basis. Admiral J. C. Wylie divides military strategy into “sequential” and “cumulative” strategies. Sequential campaigns only happen in wartime. That’s when military forces hammer the foe time after time until the foe capitulates or can resist no more. Each engagement takes place after and depends on the one that came before. The campaign can be graphed on a chart or map using a line or curve pointing toward the end goal.

Cumulative campaigns are incremental and scattershot by contrast. Individual endeavors don’t take place in sequence, either in time or in geographic space. They take place all over the map or chart, unconnected to one another. Plot their positions and it looks like you’ve splattered paint everywhere. No single engagement decides the overall outcome, yet they can add up to seismic strategic effect. Hence Wylie’s lingo.

Wylie classifies maritime strategy as a quintessential cumulative strategy, others being air strategy and insurgent and counterinsurgent strategy. And since maritime strategy operates in wartime and peacetime alike, his insight transcends the realm of warfare. It describes a host of pursuits that fall under the rubric of grand strategy, such as alliance building and maintenance, economic outreach or coercion, or military maneuvers. No single initiative brings strategic success in itself, but together they can convey the United States toward a better state of peace by increments. Grand strategy shows which  of the coauthors’ “cases” are worth pursuing and how to handle them.

Now let’s turn to the sea more specifically. The bones of a lasting U.S. grand strategy have been visible for decades. As long ago as the 1890s the U.S. Navy sea captain and Naval War College president Alfred Thayer Mahan articulated a maritime strategic vision specific to the United States. Mahan based his grand strategy on opening up access—commercial, political, and military access, in that order of importance—to important trading regions. The ability to trade in East Asia and Western Europe ranked first among his priorities. Commerce was king. Diplomatic access helped guarantee commercial access. Military and naval access was a mere enabler, safeguarding diplomatic and commercial access.

The U.S. Navy, then, was chiefly the defender of commercial shipping for Mahan and kindred navalists. The fleet prevented any hostile navy from blockading American seacoasts, saw merchantmen safely across the high seas, and ushered them into foreign harbors where they could sell their goods to satisfy buyers’ wants and needs—and, as a byproduct, generate revenue for Washington to reinvest in the navy to protect trade. Mahanian statecraft aimed at starting up this virtuous cycle of trade, diplomacy, and naval affairs and keeping it churning into the indefinite future. The maritime symbiosis he discerned persists to this day. His works found favor with President Theodore Roosevelt, his friend, and President Franklin Roosevelt, who devoured his writings as a teenager, among many others in a position to put saltwater ideas into practice.

Fast forward to World War II. That’s when Yale professor Nicholas Spykman, the dean of geopolitics scholars, applied an even keener edge to U.S. maritime strategy. Spykman presented a stark choice: the United States could content itself with hemispheric defense, an option he deemed no defense at all. Or it could entrench itself along the “rimlands” of Western Europe and East Asia to prevent any hostile power or alliance from seizing control of these maritime borderlands—and constituting a threat to the Western Hemisphere using the resources it wrested away through conquest. He implored America to embrace the latter course of action, mounting a forward defense and making itself a balancer in the rimlands.

It could prevent danger before it gathered.

Like Mahan, Spykman obsessed over nautical access. He saw the need for a navy able to command the sea—not just the high seas that bridged between continents, but what he termed the “girdle of marginal seas” swathing the Eurasian periphery, from the Mediterranean Sea at the western extreme to the South China Sea (which he dubbed the “Asiatic Mediterranean”) to the east. An oceangoing hegemon—the Royal Navy in Great Britain’s imperial heyday, or the U.S. Navy after World War II—could accomplish little in the rimlands unless it could get there. So British or American seafarers must be able to fight for command of expanses far from home. Spykman put the accent on geopolitical balancing, Mahan on trade and commerce. They both arrived at the same goal.

Access.

Now fast forward again, to the George W. Bush administration. In 2007 the U.S. Navy, Marine Corps, and Coast Guard published their first triservice Maritime Strategy, titled A Cooperative Strategy for 21st Century Seapower. The directive set sea-power specialists abuzz because it put the emphasis on preventing war rather than winning it, and for declaring that America and its partners would serve as guardians of the system of liberal trade and commerce. But Mahan and Spykman would instantly grasp—and likely applaud—its basic elements. The United States, announced the strategy’s framers, intended to station “credible combat power” in the rimlands for the foreseeable future, preserving commercial, political, and military access while deterring aggression. America meant to remain number one in maritime Eurasia.

The Obama administration published a Maritime Strategy of its own in 2015, but it hardly broke with the Bush administration’s approach. In fact, sea-service chieftains kept the same title and basic approach, calling the 2015 strategy a “refresh” of its 2007 predecessor to account for change—the rise of Communist China in particular—rather than something wholly new. The substance remained much the same. Also in 2015 the Obama administration released an Asia-Pacific Maritime Security Strategy that vowed to preserve “freedom of the sea” in the face of coastal states’—again, principally China’s—efforts to cordon off marginal seaways such as the South China Sea as sovereign territory. Spykman would cheer.