NATO leaders were united last week in their support for Ukraine's military and pursuit of new ways to economically punish Russia for its unprovoked invasion. President Vladimir Putin shows no signs of relenting, but his commanders have hinted that they may scale back their goals in response to Kyiv's ultimatum.

US and allied leaders in the Indo-Pacific should apply lessons from Ukraine or they could find themselves facing a resurgent China empowered by a decade of gray-zone belligerence.

The Russian military is consolidating its gains in southeast Ukraine around Crimea and the Donbas region — two ­areas Moscow gained through an insurgency led by mercenaries and paramilitary troops. China is lifting a page from Moscow's playbook in the South China Sea, where it has built and armed artificial islands along international shipping lanes and flight paths, and within the economic exclusion zones of multiple Southeast Asian nations. 

By extending the reach of its air defenses and anti-ship missiles to the edges of its neighbors' airspace and territorial waters, Beijing could keep its opponents' ships in port and aircraft on the ground, giving China an advantage in any confrontation. And like Russia in eastern Ukraine, China uses its long-range weapons to protect its maritime militia and coast guard in the South and East China Sea as they harass rivals' navies, fishing fleets and shipping vessels. 

US and allied militaries have done little to confront or resist China's gray-zone campaign. Freedom-of-navigation operations have failed to stop Beijing's growing control and influence in the region. The increased frequency of friendly-carrier operations may be reassuring to US allies, but China's behavior is unchanged and when the carriers leave, allies are once again on their own. 

Chinese structures and buildings on the man-made Fiery Cross Reef at the Spratlys group of islands in the South China Sea are seen on Sunday March 20, 2022.
Chinese structures and buildings on the man-made Fiery Cross Reef at the Spratlys group of islands in the South China Sea.

The Pentagon released its new defense strategy this week, which highlights "campaigning" as one of its three main actions. Although the ­unclassified fact sheet is short on details, campaigning entails operations to undermine coercion of US allies, complicate adversary decision-making, and develop US and partner capabilities.