Stealing or detonating US air support. With the new influx of volunteers the US would seem to receive, according to you and CC, it would be simplicity itself for me to slip spies in. Spies report guard times and watches at airfields, I strike with a moderate force, blow up some planes or shoot anybody who goes near them. The US, so dependent on their air support, now has to fight a force that is gunning them down as they emerge from their barracks or tents or whatever they are using. And keeping them away from their precious aircraft! My men, better suited to such conditions, shoot with better accuracy than the US troops do as a panic forms among remaining US soldiers. Any officer I see trying to organize a reasonable defense gets several snipers turned his way! After the troops inevitably surrender, I take their armaments, kick them out, and take the planes for myself, along with whatever other goodies they have in there. And if the US counterattacks? Have the planes hold off the land-based US troops while I make my getaway with my troops. Any planes that survive until we escape are to meet at a pre-designated rendezvous point, where further plans are to be made. If I have to ditch the planes, I'll either blow them up or use them in a trap for the US.
There are some major problems with that scenario.
First, you are expecting your green troops to be calm and disciplined, while the professionals panic? lol Not quite how I see it going.
But the biggest problem is your expectation that you will be able to sneak in and take a military air field. Getting a few armed men onto the base is one thing. Controlling the number of armed men that would be there is another. Have you ever been on a military air command? Do you think you will be able to SEE the officers mounting a defense? In fact, the snipers will be taking your men out in short order. They will have the advantage of better weapons, better familiarity with the terrain, better training, and better communications. You will have the element of surprise. Which will get your organization noticed, but not much more. You will not be allowed to take any serious aircraft. The security forces of the base will disable them before you do.
Also, your plan relies on complete isolation. As soon as your attack begins there will be support from other military installations. If you manage to destroy aircraft at one base, there will be greater numbers of aircraft arriving within a few hours. Now you have lost the element of surprise and your enemy's air support is as effective as it was before. And any aircraft you stole will be targeted and destroyed.