Yesterday Japan’s Air Self-Defense Force scrambled F-15 Eagle fighter jets and an E-2C airborne early-warning aircraft after a Japan Coast Guard ship spotted a Chinese plane near the Senkaku/Diaoyu archipelago. China’s State Oceanic Administration described the flight of its B-3837 patrol plane as part of air-sea operations around the islands. And indeed, such missions may become a regular feature of the Senkakus dispute.

China’s small-stick diplomacy, it appears, has taken on an aviation component. Beijing wants to show that it — not Tokyo — administers the contested real estate effectively.  There are advantages to routine flights. Aircraft can operate over the waters around the archipelago, much as ships from China’s nonmilitary sea services have for months. Planes can also overfly the Senkakus directly, whereas landing personnel on the islets could trigger a conflict. That’s a low-risk way to make a high-impact statement.  In effect Beijing can dare Tokyo to do something about it.

Aloft as at sea, showing the Chinese flag in Chinese-claimed waters and skies cultivates the image of normalcy. Military forces fight for disputed objects; the outcome is often in doubt or reversible.  By contrast, policing the skies is a prerogative, and indeed the duty, of a sovereign state. Portraying itself as the rightful sovereign over the Senkakus and the adjoining seas and airspace is precisely the point for Beijing. That’s why police services like the State Oceanic Administration are the face of Chinese policy in the Senkakus, at Scarborough Shoal, and in other territorial controversies.

In operational terms, how does air power fit into China’s toolkit for the island dispute? Aerial patrols are far from the ideal implement for the job. The late Admiral J. C. Wylie helps explain why. Wylie faults air-power proponents for conflating the power to destroy from the air with the capacity to control territory and people. Air forces, he writes, can rain destruction from the sky. But they cannot loiter on station indefinitely to exercise control. To use a law-enforcement simile, planes and helicopters are like police cruisers roaming the streets — except that, unlike police cars, they can’t stop for long, lest they crash. Their presence is episodic.

For Wylie the man with a gun standing at a key spot on the map is the true arbiter of control.  Eighty percent of life is showing up, and staying. Like the cop walking his beat, the soldier, marine, or policeman toting a gun can mount a constant physical presence, and thereby maintain order and suppress lawlessness. Sea power occupies the middle ground between a ground presence and the intermittent presence supplied by air cover. While their endurance is finite and the sea areas they monitor vast, ships can remain on scene for a long time. They can dawdle on the high seas to show the flag and perform police duty.

What does this disquisition mean for the Senkakus impasse? Ships will doubtless remain around the islets to put substance into China’s maritime claims. I doubt Beijing will land law-enforcement personnel, let alone troops, in the Senkakus. The man holding a gun would have to fight his way ashore, perhaps touching off a clash entailing vast and unforeseeable consequences. And airplanes? One imagines Japanese mariners will see them overhead more and more often. Buzzing the islands does little to enforce China’s control there. But it could well advance Beijing’s messaging campaign — helping it consolidate its image as their legitimate ruler.