The use of force during maritime law enforcement: A study of international legal standards and China’s recent practice in the Second Thomas Shoal

Maritime law enforcement refers to a range of constabulary measures to maintain legal order and protect littoral States’ interests in areas within their national jurisdiction, as well as in certain circumstances on the high seas. The use of force is one of the measures deployed by coastal States to exercise law enforcement powers, though it is subject to several constraints to safeguard its lawfulness. The coast guard agency is a common authority entrusted by States to carry out maritime law enforcement duty during times of peace. However, beyond their conventional functions, recent State practice shows that the coast guards have gradually become the primary instrument by which coastal States assert sovereignty and sovereign rights in relation to disputed maritime areas. Particularly, at the Second Thomas Shoal, the China Coast Guard frequently resorts to the use of force, such as ramming, shooting water cannons, or using lasers, as part of their law enforcement measures against the Philippines Coast Guard and resupply vessels, do not adhere to the legal standards set out in this paper. In light of the increasing frequency of forcible measures in this area, this paper emphasizes that the use of force as part of maritime law enforcement measures must conform to international legal standards, including due regard and due diligence obligations, considerations of humanity, and respect the sovereign immunity of warships, military aircraft, and government vessels on non-commercial services. Force must only be used as the last resort and must comply with principles of necessity, proportionality, and reasonableness.