For almost two decades now, national leaders have betrayed the 1987 Constitution which does not allow any permanent presence of foreign troops on Philippine soil without a ratified treaty.

Gloria Macapagal Arroyo, and her defense and military leaders had circumvented the law when they allowed the US military to set up a permanent presence in Mindanao just months after the September 11 attack in New York and Washington, D.C.

An American base was set up inside a local military camp at the Western Mindanao Command in Zamboanga City, where even local troops were not allowed to access.

The facility can receive voice communications and images from satellites, drones and surveillance aircraft and can send back any message directly to Manila, Hawaii and the Pentagon, according to local military sources.

It has been a vital listening post in Southeast Asia in the guise of advising and training local special forces to hunt down and fight a small group of violent Islamist militants.

An American security expert said nobody in Washington talked anymore about al Qaeda or the Islamic State as the Pentagon shifted its focus on big power rivalry with Russia in Europe and China in the Indo-Pacific region.

A former journalist, Teodoro Locsin Jr., and now the country’s secretary of foreign affairs, had recently placed the spotlight on US military presence in Mindanao in a cable TV interview when he admitted the US military has a permanent, not rotating presence in the south.

The troops deployed in the south could be rotating every three to six months since 2002 when they were first sent there as part of President George W. Bush’s war on terror, but the sophisticated communications and radars are permanent.

Locsin could be referring to several coast watch radar stations that Washington funded and installed in five areas in the southern Philippines. These stations were supposed to monitor and track down movements of small and swift fast boats the Abu Sayyaf Group has been using to smuggle arms, people and drugs in the porous borders between Malaysia and the Philippines.

Sadly, these radar stations had not alerted local authorities every time the Abu Sayyaf Group staged kidnap-for-ransom operations targeting foreign tourists and fishermen on the Malaysia waters.

Local military commanders had said Filipinos do not have access to these coast watch radar stations and the state-of-the-art gadget and equipment are removed each time American operators leave the facility.

The coast watch station could be monitoring movements, not of the Islamist militants, but of Chinese warships and submarines passing through the narrow straits in Balabac and Sulu Sea enroute to the Pacific Ocean.

In 1992, Washington lost its two large overseas bases in Subic and Clark after a dozen senators voted to terminate the US Military Bases agreement in September 1991.

At that time, the US was downsizing its military presence around the world, including several bases in the continental United States (CONUS) as its ideological nemesis, the old Soviet Union, was on the verge of collapse. There was also widespread unrest in China, which was reversed after the Tiananmen incident.

At the beginning of 1990s, the world’s only superpower was reduced to policing, poking its fingers into Somalia, the Balkans and Rwanda.

But defense planners in Washington have long thought of moving back into Southeast Asia as its bombers and fighters need bases closer to potential flashpoints — the Taiwan Straits.

The need for a US presence in Southeast Asia was highlighted after the 9/11 happened as Washington launched attacks in Iraq and Afghanistan.

Arroyo and her generals eagerly welcomed back the Americans, ignoring the 1987 Constitution which prohibits foreign troops on Philippine soil without a treaty.

They used the 1998 Visiting Forces Agreement (VFA) as an excuse to accommodate the Americans and went beyond by agreeing to cooperate on non-traditional military activities, like counter-terrorism.

The annual large scale, combined and joint military exercises, called “Balikatan,” resumed in April 2000 to test the operational readiness of both armed forces in case of an external aggression.

Balikatan is purely a conventional military exercise with a little of the humanitarian activities, like building schools and clinics in poor villages and providing medical, dental and veterinary care to communities.

When 1,000 US troops descended to Mindanao to advise and train local forces to hunt down and fight the Abu Sayyaf Group, two sides used the term “Balikatan” in the unconventional military activity.

The use of “Balikatan” was a violation of the law as previous exercises were done in military reservation areas on the main island of Luzon and US troop presence in Zamboanga, Basilan and Sulu were out of the ordinary.

As the US war on terror in the Middle East progressed, US planes were also allowed wider access outside military facilities as F-16 fighters made pit stops on civilian airfields in Batanes and Cebu, sometimes during unholy hours when noisy helicopters lit up the runways in Basco to guide planes to land to refuel en route to US bases in Okinawa.

It took some years for the Arroyo government to rectify the gross violation of the law when in 2005 the two countries entered into a new deal, called Security Engagement Board (SEB), an executive agreement to cover non-traditional military activity, including counter-terrorism, anti-drugs and others outside the conventional military exercises and training.

It took a decade under Benigno Aquino, before another executive agreement was signed, the Enhanced Defense Cooperation Agreement (EDCA), to legitimize US use of airfields in other parts of the country as well as build warehouses, barracks and other structures for US servicemen.

In 1992, the US lost two large overseas bases which cost them at least $200 million in annual rent, excluding military assistance in the form of foreign military financing (FMF), excess defense articles (EDA) and international military education and training (IMET).

But in 2013, they gained more access to other locations with troops and equipment rotating all year round, in effect granting US forces permanent presence without paying rent.

As the present arrangement is not enough, Locsin wants to legitimize the US military permanent presence in the south, arguing it would be beneficial to the country’s security interest as well as to keeping the balance of power in the region.

Locsin said in the interview he proposed to enter into a new executive agreement to provide cover for the US presence in Mindanao, saying previous foreign affairs secretaries were wrong when they agreed to place US counter-terrorism cooperation under the VFA.

He may have a point there. The VFA is the legal framework on how to treat US servicemen when they commit ordinary crimes outside of military activities under Balikatan exercises. It covers criminal jurisdiction and issues like custom duties and taxes as well as immigration and quarantine procedure.

Counter-terrorism is a non-military activity. Another agreement should be made for such activities, including humanitarian assistance and disaster relief (HADR) operations similar to what had happened after Typhoon Yolanda in November 2013.

However, granting US forces permanent presence outside a treaty is still a violation of the 1987 Constitution. The SEB and EDCA are executive agreements that do not conform to the basic law of the land and violate the country’s sovereignty.

There is nothing wrong in Locsin’s argument about the benefits of US military presence in the country. The Philippines has a long-standing military alliance with the United States since 1951 under the Mutual Defense Treaty.

The two countries have shared common democratic values and principles. History has time and again has proven America’s commitment to defend and protect the country against a third country.

However, the Constitution is sacrosanct. It must be respected, upheld and followed to the letter. If it allows foreign troops presence in the country only through a treaty, then, the nation’s leaders must work on a treaty and not on an executive agreement.

Arroyo and her generals had committed a grave error. Locsin must not make another.