Summer of Sink-ex

The US and its allies showed off their anti-ship prowess several times this spring and summer by blasting decommissioned warships out of the water in a series of sinking exercises across the Pacific.

The sinking exercise, or sink-ex, is a regular part of naval training. Retired vessels are stripped of fuel and components that could harm the environment and towed out to sea so militaries can test their ability to target and sink them using a variety of weapons and sensors.

But the sink-exes between May and July were notable for the new weaponry and units involved, and they show how militaries in the region are increasingly focused on developing and training with weapons to take down surface ships. While officials said the drills are not directed at a specific adversary, they come amid heightened tensions with China, which is using its large and increasingly capable navy to challenge its rivals.

The sink-exes kicked off in early May, when US, Philippine, and Australian forces sank a decommissioned Philippine replenishment ship, ex-BRP Lake Caliraya, as it floated about 9 miles off the northwestern corner of Luzon. Ships and planes launched anti-ship missiles, guided bombs, and rockets at the vessel using targeting data received from other platforms — including an Australian E-7 Wedgetail, a plane the US is preparing to buy — in a reflection of those militaries’ efforts to improve their ability to coordinate operations.

That sink-ex was the culminating drill of Balikatan, a long-running US-Philippine exercise that has grown in scope and scale in recent years. This year’s Balikatan sink-ex built on last year’s, which was the first live-fire sink-ex in the exercise’s history. It also came as the Philippines clashed with China over Beijing’s claims to Manila’s territory in the South China Sea. The fact that the ship sunk at Balikatan this year was Chinese-built was only a coincidence, Philippine officials said.

US soldiers held another sink-ex in mid-June during the exercise Valiant Shield, which involved some 10,000 US and Japanese troops and operations ranging from Hawaii to Japan. During the drill, members of the US Army’s 3rd Multi-Domain Task Force on Palau fired two Precision Strike Missiles from an Autonomous Multi-Domain Launcher at a decommissioned amphibious transport dock, the ex-USS Cleveland, as it floated 45 miles offshore.

It was the first time the missile, which has a range of more than 250 miles, and the launcher had been used outside the US and was “a significant milestone in the Army’s development of long-range fires capabilities,” the service said. It was also a milestone for the Army’s Multi-Domain Task Force — a new unit with long-range strike, air defense, and other capabilities for disrupting enemy operations — that allowed it “to test our systems and processes as well as integrate new capabilities alongside our partners and allies,” the 3rd MDTF commander said.

US Marines notched another anti-ship achievement on June 26, when a AH-1Z attack helicopter fired the new AGM-179 Joint Air-to-Ground Missile at a moving training target during an exercise in the Philippine Sea. The test was the first time the missile — which will replace the Hellfire missile and provide a “fire and forget” capability to destroy “fast-moving maritime targets” in rough seas — had been launched from an AH-1Z in the Indo-Pacific theater, the Corps said.

The sink-exes continued in July during Rim of the Pacific, a major biennial naval exercise held around Hawaii. During this year’s edition, US troops worked with Australian, Malaysian, Dutch, Japanese, and South Korean forces to sink the amphibious transport dock ex-USS Dubuque on July 11 and the amphibious assault ship ex-USS Tarawa on July 18 using ground-, air-, and ship-launched weapons.

RIMPAC usually features at least one sink-ex, but this year stood out for what was sunk and how. The 40,000-ton Tarawa was the first ship of its kind used in more than a decade and one of the largest ever sunk at RIMPAC. (The only other Tarawa-class ship sunk at RIMPAC was the ex-USS Belleau Wood in 2006.) The ship’s inclusion prompted speculation about the US and its allies testing their ability to sink a carrier or large amphibious ship, like China’s Type 075 landing helicopter dock, which is similar in size to Tarawa-class ships. (China certainly noticed the similarities.)

Vice Adm. John Wade, commander of the US Navy’s 3rd Fleet and of the RIMPAC combined task force, said beforehand that the Tarawa’s size would allow for “multiple events with multiple weapons” and “gives us an opportunity to have a hulk that will last for hopefully a long amount of time so we can get all of our drills through and successfully executed.”

The Dubuque sink-ex again featured an Army MDTF, which worked with Japanese soldiers to fire Japan’s Type 12 anti-ship missile. During the Tarawa sink-ex, a US Navy destroyer and an Australian navy destroyer both fired the Naval Strike Missile — a stealthy anti-ship cruise missile that is an upgrade over the aging Harpoon missile — for the first time.

Perhaps the most notable were the new air-launched weapons fired at the Tarawa. A US Navy fighter jet launched a Long-Range Anti-Ship Missile, “a precise, stealthy, and survivable cruise missile,” and a US Air Force B-2 stealth bomber employed a Quicksink munition, a smart bomb modified to be an “air-delivered method for defeating surface vessels.”

New units and new weapons for new threats

While practicing to sink ships is nothing new — US pilots have been doing it for over a century — the new weapons and units deployed in sink-exes this year showed how the US and its allies are intensifying their focus on anti-surface warfare in response to the growing threat they see from China’s expanding navy.

The effort to increase US stocks of anti-ship weapons has taken on new urgency after the rapid expenditure of weapons seen during the war in Ukraine. LRASM, which is being developed for the US Navy and Air Force and which allies are buying, and the Air Force’s Quicksink project are both meant to boost that arsenal. Quicksink in particular is meant to supplement stockpiles by quickly and cheaply adding a seeker for maritime targets to smart bombs. There is doubt that Quicksink can replicate the effectiveness of torpedoes, but it is seen as a way to bring more weapons to bear against surface ships.

The US Air Force is stepping up its training to employ those and other weapons against increasingly well-defended Chinese warships, and other service branches are developing units for similar missions. The Marine Corps’ Marine Littoral Regiments are meant to disperse within range of enemy weapons and avoid detection while conducting operations like intelligence-gathering or launching anti-ship missiles. The Army sees its MDTFs as a complementary force, operating from strategically important areas, like Japan’s southwest islands, to conduct strikes against enemy warships, aircraft, and ground forces.

Those initiatives have set off inter-service squabbles over responsibilities and resources, but Pentagon leaders have largely come to the view that they need more weapons and better coordination across services and with allies to employ them — “stacking effects” to take down Chinese warships and other hard targets.

Each military branch “brings capabilities” to counter China in the Western Pacific, Gen. Kevin Schneider, commander of US Pacific Air Forces, told me in an interview in July. “It is not purely a US Air Force vs. PLA Navy fight. The entirety of the joint force and the effects that we bring across the spectrum all come to bear.”

US allies have similar initiatives. Japan’s military is shifting its focus to the country’s southwest islands and developing new amphibious units to defend them. Tokyo is also acquiring new anti-ship missiles, including US-made Tomahawks and upgraded Type 12 missiles, to ward off invaders. The Philippines is acquiring BrahMos anti-ship missiles and pursuing other new weapons, including submarines, amid a broader reorientation to defense against external threats. Taiwan is buying US-made Harpoons, upgrading its older anti-ship cruise missiles, and setting up new bases for those weapons.

US-led exercises like RIMPAC are opportunities for those militaries to practice using those weapons, even if sink-exes themselves don’t really replicate what it’s like to use them against a live enemy.

For buyers of US hardware, “this is a good chance for them to go out and actually have their guys launch it, blow something up, and say 'OK, I got it. I understand how this works. I feel confident when I use it in the field.’” Bryan Clark, a senior fellow at the Hudson Institute, told me after RIMPAC in 2022, when a decommissioned US Navy frigate was sunk. (During that sink-ex a Malaysian navy ship fired a missile outside Malaysian waters for the first time.)

“That's really the main purpose behind those exercises,” Clark said. “They don't really represent like a situation you'd really face against a Chinese warship.”

Years of sink-exes and related training has given US sailors plenty of practice, but the investment in new weapons shows that experience isn’t the only concern. “The issue that the US Navy has is do they have enough of these weapons to actually do these operations on a sustained basis if there was a fight, just like we saw with Russia in Ukraine,” added Clark, a former US Navy officer. "You might run out of weapons really fast, and that I think is a bigger issue than the proficiency of the force.”