Air bases in Luzon have become increasingly important to the United States as tensions rise in the Taiwan Straits, just north of the Philippines.

Under the Enhanced Defense Cooperation Agreement (EDCA) signed in 2014, Washington was allowed access to five military bases in the country, where fighters, surveillance planes and other aircraft operated by the United States Air Force and Navy can rotate for a limited time.

The US Navy’s P3C-Orion anti-submarine planes, and much later, the P8 Poseidon, had been landing and taking off at Clark Field even before EDCA was sealed.

Clark Field, the former home of the US 13th Air Force, was not even included among the four air bases and an army jungle training base in the EDCA list.

During the Benigno Aquino administration, Washington also sought access to civilian airfields, like the Laoag International Airport in Ilocos Norte, where it could launch unmanned aerial vehicles (UAVs) to monitor situations not only in the South China Sea but in the Taiwan Straits.

It was not only convenient for the United States to use air bases in the Philippines, it was also more practical than having its surveillance aircraft fly from Okinawa or Guam. The P3C-Orion planes will have more loiter time and can easily refuel and return to its mission.

In 2019, several American F-16 fighters from US bases in South Korea held the seventh iteration of the Bilateral Air Contingent Exercises-Philippines (BACE-P) at Basa Air Base in Pampanga, an air force-led drill, after Manila acquired fighter capability — a squadron of FA-50s Golden Eagles.

The Philippines retired its remaining fighters, F-5A/Bs Freedom Fighters, in 2005. For about a decade, the Philippine Air Force had no fighter capability. It was only at the tailend of the Aquino administration when a South Korean aerospace company delivered its first FA-50s aircraft.

The US got a bonus when it gained access to air bases in the Philippines because it could train in an air gunnery range at Crow Valley in Tarlac, one of the few air force training grounds in the region. US aircraft can drop bombs, deliver rockets and strafe targets on the ground, which it used to do when the US had two large overseas bases in Clark and Subic, which closed in 1992.

The air bases in Luzon became more valuable to the Americans as temperatures have risen in Taiwan’s maritime borders and airspace, with China sending waves of its People’s Liberation Army Air Force (PLAAF) planes — fighters, bombers, and maritime surveillance aircraft — into Taiwan’s air defense identification zone (ADIZ) almost daily.

In October alone, China sent more than 150 aircraft into Taiwan’s ADIZ, testing the tiny island’s readiness to respond to provocations.

However, the Chinese aircraft avoid flying deeper into Taiwan’s air space. Most of the time, the PLAAF’s J-6 and J-10 fighters and Y-8 surveillance planes also violate parts of the Philippines’ ADIZ in extreme northern Luzon.

The Philippine Air Force rarely scrambles its FA-50s together. Recently it sent two FA-50s to intercept an unidentified aircraft into its ADIZ near Pangasinan. The unidentified aircraft changed course and moved away five minutes before the air force could intercept the plane.

Taiwan has been scrambling fighters to intercept Chinese planes intruding into its ADIZ but the daily operations have been taking a toll on the Taiwanese aircraft. At one point, Taiwan stopped sending fighters to intercept Chinese intruders.

But Taiwan has been stepping up its defenses, anticipating a full-blown invasion of the island to reunite with China, which considers the tiny state a renegade province.

Taiwan’s defense ministry has requested for increased funding to upgrade and improve its capability to deter Chinese aggression and to ramp up its reserve force training.

Washington has also promised to protect Taipei, warning Beijing to end its provocations. US State Secretary Antony Blinken had squared off with China’s Foreign Minister Wang Yi over Taiwan.

Some Republican senators have called on the Biden administration to increase defense spending in Taiwan, allowing it to procure advanced weapons systems to defend itself.

The Philippines offers the best strategic location for the US to launch any activity in both the South China Sea and Taiwan Straits, just north of extreme northern Luzon. In fact, Taiwan and the Philippines have overlapping 200-nautical-mile exclusive economic zones and ADIZs.

The restoration of the 1998 Visiting Forces Agreement (VFA) by President Duterte in July and the change in government next June are positive developments for the United States.

Washington is hoping a friendlier government will replace the pro-China administration as it ramps up its military exercises and training as well as its hunt for logistics hubs under its new integrated deterrence strategy in the Indo-Pacific region.

The US has been prepositioning its forces, equipment and supplies in the region, reducing the vulnerabilities of its large overseas bases in Japan and South Korea.

The US will spend about $150 million in experimentation, innovation and exercises next year in the region under the $5-billion Pacific Deterrence Initiative (PDI) budget passed by Congress as a follow-through to the Asia Reassurance Initiative Act (ARIA) under former President Donald Trump.

The annual joint and combined bilateral “Balikatan” exercises are included in three large-scale drills funded under PDI in fiscal year 2022, the year the Philippines and the United States agreed to expand the activities and invite Australia, Japan and the United Kingdom to send token forces and observers.

The two allies are planning to increase the 353 activities under the Mutual Defense Treaty to over 400 training and subject matter expert exchanges next year.

US forces will be rotating troops and equipment in five local bases and other areas, like Clark, Subic, Manila, and even in tiny Batanes, which will become important.

Even before tensions in Taiwan rose, the US had been using the civilian airport in Basco, Batanes for refueling, for aircraft coming from long flights from Diego Garcia in the Indian Ocean to Okinawa during the war on terror in 2003.

The importance of the country’s location can influence regional security as well as the intense rivalry between Washington and Beijing.

As US and China’s rivalry heats up, the outcome of next year’s Philippine elections is also important for both powers. In the last five years, China won some points as Duterte distanced himself from the US. But the defense and foreign affairs departments have championed US interests in the country.

Will the superpowers meddle with the country’s balloting next year? That is the big question. Perhaps they are interested, and some presidential aspirants have revealed their links to certain powers.

The South China Sea dispute, China-Taiwan tensions and the big powers game will definitely become an election issue.