In a month-long standoff between China and the Philippines over a disputed shoal in the South China Sea, Beijing has so far refrained from sending warships from its increasingly powerful and modern navy to enforce its territorial claims.

Instead, China has deployed patrol vessels from its expanding fleet of paramilitary ships to Scarborough Shoal, known in Chinese as Huangyan Island. Naval experts say the intent is to minimise the risk of conflict and contain any regional backlash.

After alarming some of its neighbours in recent years with assertive behaviour in the South China Sea, China has turned to “small stick” diplomacy, using unarmed or lightly armed patrol boats from fisheries, marine surveillance and other civilian agencies rather than warships.

Shen Dingli, a security expert at Shanghai’s Fudan University, said the role of these vessels was to demonstrate “soft power” and avoid the impression that China was engaged in…