I propose America consider moving back to the Cold War-era model of one or two major facilities, with the likeliest candidates for retention being al-Udeid Air Base in Qatar and West al-Mubarak Air Base in Kuwait, which is currently under construction and due to open in 2023. Though not as robust as a seaport, each base could facilitate the reintroduction of additional American forces, should the need arise.
I'd also like a port--like Duqm, Oman--since no airfields are sufficient for the logistics and our Navy would need a safe harbor.
We can't be strong everywhere and changing circumstances should allow for changes in deployments. Our military presence has gone up and down as threats have waxed and waned (see Iraq and Afghanistan).
And yes, we can return to places we leave (see Europe where we are rebuilding our military presence).
Still, my worry is that leaving could provoke problems that require an even bigger return (see Iraq from 2011 to 2014), or allow others who aren't friends to fill the vacuum.
That said, nothing should be written in stone. Although the one thing not discussed is whether the question should be whether our air-land focus on the Middle East itself to prevent threats from emerging from the Middle East should actually be changed to an air-sea focus on the Arabian Sea and Indian Ocean to face external threats to the region.
If we can support the governments in Iraq and Afghanistan who now work with us to kill jihadis rather than being run by people who support terrorism, the switch to the latter mission is a no-brainer, with only the timing the issue.
