Australia should establish a coast guard to counter China's use of grey zone tactics in expanding its territorial claims in the South China Sea. China is using its coast guard, along with civilian vessels and fishing boats, to impose its presence, so Australia and its regional partners should respond in kind.

A dedicated, militarised coast guard would be more effective than joint naval patrols in conducting a proportionate response to Chinese aggression and less likely than direct naval approaches to escalate tensions. An Australian coast guard could build on recent collaborations with the US Coast Guard to match China's tactics in the region.

Whether or not Australia needs a coast guard is a recurring question in national security circles. Experts point to the lack of resources within the Royal Australian Navy (RAN) to defend Australia’s coast, support allies and protect national interests abroad. A coast guard would reduce the navy's responsibilities by taking the lead on local constabulary and border protection operations, freeing up the RAN to focus on the business of warfighting.

Furthermore, a coast guard could support the RAN in facing unique threats at sea, namely China’s use of grey zone tactics in its campaign to expand its territorial claims in the South China Sea. Grey zone tactics are designed to coerce other states without rising above the threshold for conventional retaliation.

As an island nation, Australia depends on open sea lines of communication (SLOCs) for the movement of goods and security forces, and China’s territorial claims have the potential to constrict these important passages. Canberra has repeatedly emphasised the importance of free and open SLOCs in its defence policy, and its commitment to a free and open Indo-Pacific in its national security strategy. The 2017 Foreign Policy White Paper said Australia relied on its SLOCs to connect with the world, and the 2020 Defence Strategic Update stressed the importance of access through the Indo-Pacific for security and trade.

Despite the commitment of Australia and other countries to upholding international law and freedom of navigation, China is steadily making gains in the South China Sea, using its coast guard and ostensibly civilian fishing boats to engage in grey zone tactics.

These tactics put the United States and Australia in a difficult position. If they deploy their warships, China can accuse them of escalating the situation. So, to fight and win in the grey zone, they must also use grey zone tactics and send out civilian vessels—fishing boats and the coast guard ships.

The US Coast Guard has been considering this strategy since 2017 and recently moved the homeport of its cutter Harriet Lane to Pearl Harbour to help South Pacific partners police their exclusive economic zones. Indeed, Australian Border Force officers travelled on Harriet Lane in March as part of Operation Blue Pacific Patrol.

This kind of constabulary cooperation could provide a model for proportionate response to China’s tactics. The deployment of Harriet Lane was not directly aimed at China, but it provided scope for the US to respond to China's coast guard with corresponding force. China has already protested against the US Coast Guard’s law enforcement activities in the South Pacific.

If Australia wants to counter Chinese aggression without escalation, it must develop its own constabulary maritime force. A forward-deployed coast guard could go head-to-head with China in the South China Sea, working in collaboration with the US (and possibly Malaysian, Indonesian, Vietnamese or Philippine police as sea riders). A dedicated constabulary force would permit a proportionate response, while preventing high tensions from inadvertently escalating into war.

An Australian coast guard would play a balanced role in countering China in the South China Sea. Joint patrols make for good press releases but don’t deter Chinese aggression, while direct naval approaches risk escalating tensions. A constabulary force would lessen this risk and permit a proportionate response. A dedicated, militarised coast guard would allow Australia to set up the right configuration of forces to make an effective stand. It wouldn’t be a quick fix, but it’s what Australia needs to win in the grey zone.