And lastly, China went big, and fast, elsewhere in the Spratly and Paracel archipelagoes. Starting in 2013, civil engineers manufactured island bases from rocks and atolls scattered across the South China Sea. Chinese president Xi Jinping pledged not to “militarize” the artificial islands, freezing any serious response from the Obama administration, only to proceed with construction of airfields and other infrastructure. The result: a fait accompli.

It’s one thing to deter an aggressor from seizing ground, quite another to evict an aggressor from ground it has already seized. Island-building tactics of all three varieties have left China in possession of territory—and it’s hard to see how such gains can be reversed short of open warfare. Beijing has, in essence, forced the region and the United States to live with a new and largely irreversible strategic reality.

This typology of gray-zone tactics suggests that China is bringing to bear all elements of national power on the maritime disputes in the East and South China Seas. Beijing has employed legal, diplomatic, maritime and material elements of statecraft to chip away at the U.S.-led liberal international order. Even its construction prowess, honed over decades of massive infrastructure-building, has been on dazzling display in the heart of the South China Sea—contributing to strategic success.

For custodians of the current order, consequently, it is not enough to think exclusively about the marine dimensions of strategy. To balk China’s gray-zone stratagems, Washington and its allies must take a page from Beijing and adopt a holistic, grand-strategic posture that applies patient, vigilant countervailing pressure on many fronts simultaneously. In short, the defenders of the status quo must think in shades of gray and must accustom themselves to acting in the twilight between peace and war. To do any less would concede to China the initiative—and the future shape of the regional order.

Thomas Schelling would nod knowingly at the challenges before Washington and its partners. Unlike his milquetoast parents, let’s muster some strategic discipline.

James Holmes is J. C. Wylie Chair of Maritime Strategy at the Naval War College and author of “Visualize Chinese Sea Power,” in the current issue of the Naval Institute Proceedings. The views voiced here are his alone.

This article is being republished due to reader interest.

Image: Reuters.