"[20] After the eruption of Mount Pinatubo in June 1991, the US decided to abandon nearby Clark Air Base, which had been heavily damaged by ash emissions and lahar flows.

[21] An emergency evacuation of all non-essential military and U.S. Department of Defense civilian personnel and their dependents from Clark Air Base and U.S.

[22] In July 1991, the negotiators agreed on a draft agreement titled the Treaty of Friendship, Peace and Cooperation, proposing the clean-up and turn over of Clark to the Philippine government in 1992, and extending the lease of Subic Bay Naval Base by the US for ten years.

The Anti-Bases Coalition, founded by senators Jose W. Diokno and Lorenzo Tañada led the call to end American military presence in the country.

The establishment of the US bases, particularly of Fort Stotsenberg, Clark Airfield, Subic Bay, and John Hay, frequently resulted in the displacement and disenfranchisement of the Aeta and Ibaloi indigenous peoples who lived in the land, at a time when they were already facing pressures from the incursions of civilian lowlanders.

[27][28] None of these indigenous peoples were properly compensated at the time the bases were established,[27][28] and they remain marginalized and unable to return to their historic lands today.