U.S. Marines with the 3rd Marines Regiment conduct a simulated beach raid and live-fire exercise during Amphibious Landing 2015 at Naval Education and Training Center, Philippines, on Oct. 9. A recent Philippine supreme court ruling grants the U.S. military access to five military airfields, two naval bases and a jungle training camp.

A plan to put U.S. military forces on Palawan, a Philippine island near disputed territory in the South China Sea, could herald a new era of brinkmanship with China, defense experts say.

While the move would likely ease concerns of U.S. allies over China’s aggressive expansionism in the region, it also would move an American presence right on the edge of what Beijing considers its backyard.

The Supreme Court of the Philippines gave the green light last month to an Enhanced Defense Cooperation Agreement allowing U.S. forces to build facilities, store equipment and rotate forces through the nation’s military bases. The agreement grants the U.S. access to five military airfields, two naval bases and a jungle training camp, Philippine military spokesman Col. Restituto Padilla told the Philippine Daily Inquirer.

The facilities include three on the main island of Luzon — Basa Air Base in Pampanga province, Fort Magsaysay in Nueva Ecija province and Clark Air Base in Pampanga; two on the central island province of Cebu — the Cebu naval base and Benito Ebuen Air Base; one on Mindanao island — the Lumbia airfield in Cagayan de Oro; and a naval base and the Antonio Bautista Air Base on Palawan facing the South China Sea.

In addition, the U.S. is seeking access to three civilian seaports and airfields on Luzon, including the port at Subic Bay, a former U.S. Navy base, a senior Philippine defense official told Reuters.

This would give the U.S. its first large-scale military presence in the Philippines since 1992, after negotiations on a new lease agreement for American bases broke down and the last of 40,000 U.S. personnel stationed in the country left Subic Bay.

The agreement is dependent on the outcome of May’s presidential elections in the Philippines because a new administration could scrap the deal regardless of the court ruling.

If the deal stands, however, it will put real teeth into America’s “Pacific pivot” policy, David Johnson of the Center for Advanced Defense Studies, a Washington-based think tank, said in a telephone interview Tuesday.

The presence of American forces beyond Japan and South Korea would affirm the U.S. commitment to the Western Pacific and serve as a Cold War-style “trip wire” guaranteeing a U.S. response to military aggression against U.S. partners in the region, Johnson said.

U.S. officials have publicly downplayed the strategic implications of an American military return to the Philippines, a former colony, perhaps to avoid worsening relations with China.

Marine Corps Forces Pacific spokesman Chuck Little said the Marines aren’t interested in having a permanent presence of operational forces in the Philippines.

“For the Marines, this means we should be able to visit the Philippines more often to train with more Philippine military units at more locations,” he said in a telephone interview Tuesday.

The Marines’ MV-22 Ospreys proved their ability to deploy rapidly for relief efforts after Typhoon Haiyan battered the islands in 2013. The Okinawa-based tilt-rotor aircraft will allow Marines to get to the Philippines and other parts of the Pacific more rapidly than in the past, Little said.

“We plan to come to train with our partners in the Armed Forces of the Philippines from our bases in Japan, and in the near future Guam, and then return to those bases when the training is complete,” he said.

The Marines also want to travel occasionally to the Philippines from bases in California, either for major exercises or when Marine Expeditionary Units are embarked aboard amphibious ships in the region, he said.

However, Johnson said that although “rotational forces” include occasional training visits, they might also involve a longer-term presence. Claims that U.S. forces are going there to help with counterterrorism or to prepare for disaster-relief missions “aren’t fooling anyone,” he said.

In fact, the Chinese — engaged in bitter maritime disputes with the Philippines and several other nations in the region — could regard missiles carried by U.S. ships rotating into Palawan the same way Americans thought about Russian missiles in Cuba in the 1960s, he said.

From Manila’s perspective, the agreement boosts its position in the dispute with China, he said.

“When implemented, it will vastly increase the risk of U.S. involvement in a regional conflict with China over issues that may not be of vital national interest to us, creating a near permanent state of brinksmanship, but, on the other hand, be a very strong signal of our commitment to the national interests of regional allies,” Johnson said.

Jan Van Tol, a senior fellow at another Washington think tank, the Center for Strategic and Budgetary Assessments, said that operating from bases on Palawan would put U.S. forces close to the disputed Spratly Islands, where China has been reclaiming land and building airfields and other facilities.

“More visits to the Philippines means more ships in the South China Sea,” he said in a telephone interview Tuesday.

Littoral combat ships rotating through Singapore will likely visit ports in the Philippines in the near future, he added.

“What’s important isn’t so much the ship type as the American flag,” Van Tol said.

The basing agreement reversed a longtime Philippine policy of keeping foreign forces off its soil and reflects its level of concern over Chinese expansionism as well as U.S. resolve to remain a major player in East Asia, he said. It is part of an effort that includes freedom-of-navigation operations the U.S. Navy conducted in the South China Sea last week, he said.

Down the road, the agreement will lead to more U.S. forces in and near the South China Sea and more training with partner militaries in the area. It will help counter perceptions that U.S. security guarantees might not be credible in the region, Van Tol said.

“Increased presence, and in particular increasing numbers of freedom-of-navigation operations in the South China Sea to continue to assert our rights under international law, as the secretary of defense just indicated would be happening, will be important signals of increasing peaceful resistance to Chinese coercive activities,” he said.

Indirectly, a larger and more frequent U.S. presence there may give increased confidence to partner states such as Australia to conduct similar operations asserting their rights under international law, which would be useful in countering depictions of what’s going on as a primarily U.S.-China competition, Van Tol added.

Michael O’Hanlon, a senior fellow at the Brookings Institution, another Washington-based think tank, said by email that the basing agreement won’t make much difference at first, but it will emphasis Washington’s commitment to its alliance with the Philippines as the U.S. presence becomes more consistent and more common.

“That does not answer the question of what we would do about a specific territorial dispute,” he said. “It is no magic elixir for resolving such matters or for guaranteeing a favorable outcome for Manila in any showdown with Beijing. But it should, at least, reduce any Philippine worries that China would escalate a dispute to a direct attack on a main populated island. I would think that such escalation, unlikely in the first place, will become harder for China and much riskier.”

robson.seth@stripes.com