Matt and Spencer greet the news that China will contribute to anti-piracy efforts with a bit of faux surprise; the motivating concept behind the most recent Maritime Strategy and its predecessor, the 1000 Ship Navy, holds that naval power isn’t zero-sum. Galrahn has a good discussion here considering piracy as the quintessential test of the 1000 Ship Navy concept. Of course, the Maritime Strategy includes a component on the deterrence of peer competitors, but part of that deterrence involves the integration of such competitors (Russia, China) into multilateral arrangements so that the potential competitors have a stake in international society. Incidents like this, in which thirty Chinese crewmen were rescued from pirates by multinational forces, are hoped to reinforce great power commitment to multilateral norms.
The Maritime Strategy is high liberal internationalism; it’s founded on the concept of cooperation in an arena traditionally reserved for competition, and spreading the costs (and benefits) of hegemony as widely as possible. The rescue operations following the 2004 tsunami represent another manifestation of the Strategy.
On the issue of piracy more generally, see this interview with a pirate, this discussion of the effectiveness of assaults on pirate bases, and this discussion of the role played by Kenya in Somali piracy.