Getting into a fight may not be wise, but some sort of military clash between the United States and Iran appears increasingly likely.

The latest milestone on the route to war: a combined drone and missile strike on Saudi Arabia’s Abqaiq oil facility and Khurais oilfield. Iranian-backed Houthi rebels in Yemen claimed credit for the September 14-15 attack, while Saudi officials contended that it came from the north—not from Yemen, in other words. Either way, Riyadh fingered Tehran for the assault, observing that the perpetrators carried it out using Iranian weapons.

Secretary of State Mike Pompeo termed the attack an act of war. President Donald Trump struck a more noncommittal note, postponing action while declaring that Riyadh must take part in any counterstroke. This will not be a one-on-one fracas pitting the United States against the Islamic Republic. Which seems fitting. Why help an ally unwilling to help itself?

Suppose the Trump administration opts to proceed. Not to sound sympathetic with an antagonist, but a little empathy seldom goes amiss. If Tehran’s conduct seems mysterious or unduly bellicose, it’s because from the Iranian standpoint a kind of limited war has been raging for some time. Or, if you prefer, you might call it an American “gray-zone” campaign that strikes at Iranian economic and warmaking capacity. Not cruise missiles but lost export revenues have impoverished the Islamic Republic’s standing in the region.

China, of course, is today’s leading purveyor of gray-zone strategies. Not aircraft carriers or guided-missile destroyers but unarmed or lightly armed fishing craft and coast guard cutters are Beijing’s implements of choice for, say, upholding its claims to “indisputable sovereignty” in South China Sea waters. Winning without fighting is the point of this peculiar variety of strategy. As Johns Hopkins professor Hal Brands defines it, gray-zone strategy is “coercive and aggressive in nature” yet deliberately remains “below the threshold of conventional military conflict and open interstate war.”

Prosecuted deftly, says Brands, gray-zone operations deliver “gains, whether territorial or otherwise, that are normally associated with victory in war. But they do so “without escalating to overt warfare, without crossing established red-lines, and thus without exposing the practitioner to the penalties and risks that such escalation might bring.” Beijing wants to accomplish its goals in the South China Sea without resort to violence, so it deploys the coast guard and maritime militia. If it does have to fight, at least the onus will fall on its rivals to pull the trigger first—and bear the blame for the outbreak of war.

Washington wants to face down Tehran without resort to violence, so it applies “maximum pressure,” levying economic sanctions to squelch Iranian oil exports. In both cases, China and the United States, gray-zone methods stoke ill will among their targets. Beijing is wresting natural resources from Southeast Asian neighbors while abridging freedom of the sea. The White House is choking off Iranian national income and thus obstructing Tehran’s effort to make itself the hegemon of the Persian Gulf region.

But China has an advantage over the United States lacks: it cares about its goals as much as its Asian rivals care about theirs. As martial sage Carl von Clausewitz teaches, the value a contestant assigns its “political object,” or goal, determines the “magnitude” of resources it expends to obtain that object as well as the “duration,” meaning how long it keeps up the expenditure. That means an overmatched but impassioned contender may hold a competitive advantage over a brawny but lackadaisical opponent.

The former has less to put into an endeavor but is prepared to spend what it has at a quicker rate—and for longer. The latter boasts more resources but is stingier about parting with them. Who wants it more matters.

Clausewitz might say China is better positioned to wage gray-zone campaigns than the United States because of where encounters take place on the map. That’s because Beijing is trying to manage events close to its shores while Washington is trying to face down an antagonist on the far side of the world, in a theater of secondary importance. China brings far more resources to its effort in the South China Sea than do rival contenders like Vietnam or the Philippines. It also cares as deeply about its interests—sovereignty, natural resources—as they do about theirs. It’s prepared to spend lavishly out of a far more capacious treasury of wealth and military might. As a result a lopsided advantage resides with Beijing.

Not so for America in the Gulf region, where the balance of passion markedly favors Iran, the home team, even though the Islamic Republic labors at a material disadvantage vis-à-vis the United States and its Gulf Arab allies. This is hard to see. Americans have viewed economic warfare as a routine instrument of peacetime diplomacy since the earliest days of the republic. It stirs little popular sentiment. Iranians view it as, well, warfare. It stokes competitive fire.

In short, the Islamic Republic is no pushover in Clausewitzian terms, no matter what statistics gauging raw economic and military power might say. Success is no sure thing for the U.S. gray-zone campaign.

Suppose the confrontation cascades from the gray zone into the black-and-white realm of armed conflict. How would it unfold?

Let’s ask the late, great Admiral J. C. Wylie. During the late 1960s Wylie published a winsome book that hits on a basic way of classifying military strategies: the disparity between “sequential” and “cumulative” operations. Sequential operations do just what the phrase implies. Commanders string tactical actions one after another in time and space until they reach the final goal. Each action comes after the one before and depends on it. A vector or continuous line on the map conveys the essence of a sequential strategy.

The cumulative approach is a different beast altogether. It involves mounting lots of tactical actions unconnected to one another in time or space, and wears down an opponent by administering a thousand minor cuts. It’s entirely nonlinear in nature. Plotting a cumulative campaign on the map or nautical chart produces a paintsplatter effect. Air, submarine, and insurgent and counterinsurgent warfare are quintessential cumulative warmaking methods. Such operations point toward no final objective, says Wylie, and so they aren’t war-winning strategies by themselves.

But they are a difference-maker when paired with sequential endeavors. The slow grind bestows an edge on one evenly matched foe over another.

Wylie would raise an eyebrow when projecting likely U.S. and Iranian strategies for a Persian Gulf conflict. Because sequential strategies are decisive, the stronger contender will generally searches out a sequential pathway to victory while augmenting the linear campaign with cumulative operations at the margins. A Gulf war might invert that pattern. Think about it. In all likelihood a sequential U.S. strategy would involve ground operations aiming at . . . what, precisely? Dismantling Iranian surface-to-surface missile sites? Ferreting out nuclear-weapons R&D sites? Overthrowing the regime in Tehran?

Those are all daunting prospects. One hopes such options inspire little relish among policymakers—especially at a time when Washington claims to be downgrading the Gulf on its priorities list to free up resources to compete with the likes of China and Russia. The opportunity costs of war in the Gulf could prove debilitating elsewhere along the Eurasian periphery. That leaves cumulative strategies. And indeed, U.S. officials talk of naval blockades, cyberattacks, and aerial offensives—cumulative enterprises all. Doubtless America and its allies can inflict pain through the scattershot approach to combat—but can cumulative actions compel a Tehran that is nothing if not stubborn to do the allies’ bidding?

Wylie would voice skepticism.

By contrast the Islamic Republic—the lesser contender by any objective measure—might be eager to merge a sequential component into a mostly cumulative campaign. The cumulative dimension is plain. In fact, Tehran is arguably prosecuting cumulative operations in the gray zone now. The Islamic Revolutionary Guard Corps Navy (IRGCN) is always on the go in the Strait of Hormuz and its approaches and has been particularly active this summer. For instance, IRGCN vessels detained the British tanker Stena Impero in July after the British authorities apprehended the Iranian tanker Grace 1 off Gibraltar earlier that month.

Meanwhile Tehran has kept up support for Houthi rebels in Yemen and, to all appearances, was complicit in the missile attacks on Saudi Arabia. These too are cumulative ventures. Over the years, though, Iranian leaders have signaled that they would love to land a sequential blow against the U.S. Navy in time of war. In all likelihood that means striking at an aircraft-carrier task force prowling offshore. Some of this is bombast for sure. Still, Iranian grandees may give it a try. Why exempt U.S. naval forces raining ordnance on Iran from the heaviest counterpunches the Iranian armed forces can dish out?

Iranians may also take heart from “Millennium Challenge 2002,”  the U.S. joint-forces war game when an unnamed “red team”—Iran, thinly veiled—pummeled a U.S. Navy carrier task force with the resources then in the Islamic Republic’s inventory. Retired U.S. Marine lieutenant general Paul Van Riper oversaw the red-team effort, making up for Iran’s dearth of brute firepower through ingenuity. For instance, he passed information and orders through motorcycle messengers and flashing-light signals reminiscent of World War II. Van Riper resigned in disgust when the game masters rejiggered the rules of engagement to help U.S. forces win.