So, what's to stop these other countries from basically kicking out the US military?
As long as they're happy to take our money (and our offers of defensive cooperation), we're happy to fight our wars on their territory.
In 1991 the Philippine government was in the process of not renewing the American lease on Clark Air Base. Negotiations were tense and unproductive, and it looked like the U.S. Navy would also lose the Subic Bay base.
My submarine (USS NEW YORK CITY) was on a Western Pacific deployment, doing what submariners don't discuss. Our next scheduled stop was a Singapore portcall. However Philippine liberty has been legendary since at least the Battle of Leyte Gulf (perhaps even back to the Spanish-American War), and the crew didn't want to miss out on what might be our last chance to
wallow in Olongapo City have more maintenance done in Subic Bay. We talked it over with the chain of command, sent off a few messages, and ended up getting new routing to Subic.
I'd never been to Singapore and I'd already been to Subic Bay once, so I was equally happy with either location.
We'd read reports of sporadic venting from a formerly inactive volcano over 20 miles north of Subic Bay, but it didn't seem relevant to our liberty plans. When I checked in with my spouse, a Navy meteorologist, she was livid with anger and concern at our cavalier attitude about the volcanic activity. I had plenty of time to regret reassuring her that we'd be careful.
It was nearly a week of fun & games until Mount Pinatubo erupted during Tropical Storm Yunya and dumped several feet of ash on both Clark and Subic bases. We had wind gusts up to 120 MPH. Several buildings on the base were destroyed by earthquakes. Both bases were damaged to the point of needing months of repairs & cleanup.
Our crew and our submarine survived, with injuries & damages. I was the duty officer during the eruption and the surface OOD for our eventual evacuation. It was the worst 36 hours of my life. It was the worst 36 hours of my spouse's life too, as she practically lived in the PACFLT command center, monitoring our SITREPs until we reported our underway.
A month later, after evacuating the rest of the U.S. military personnel, families, and air-worthy aircraft from Subic & Clark, the U.S. military walked away from the negotiations (and from both bases). The RP government eventually dealt with the repairs and cleanup. (Perhaps with some disaster-relief funding from the U.S.) Today both areas are largely industrial & commercial with some bases for RP military units. The U.S. routinely makes portcalls and short-term deployments to both locations, with diplomatic clearance from the Philippine government.