A massive what if but its constantly being thrown up as the "ultimate" excuse to keep going forward with what everyone know is a flawed program.
So what happens if the F-35 is canceled? Oh and before you go one step further this is just an off the top of the head, arm chair general list. I'm sure there are better ideas floating around...probably inside the Defense Depts and Ministries of the countries involved. This is just an exercise in "what if" thinking.
USAF.
The main problem for the USAF isn't that they will be losing the F-35. The problem for them is that they will have to admit that a concept has gone beyond its shelf life. That concept? Stealth! But to the issue at hand. The USAF could simply opt for new build Advanced F-16's. They could take advantage of tech developed for the F-35 and revive proposals from the past. Fitting F-22 engines into the F-16. Building the F-16XL air frame. Working with the US Navy to develop aerial lasers. Taking as much of the sensor fusion from the F-35 that can quickly and affordably put into the Advanced F-16....but again. The problem isn't stealth. The problem is concept. The lowest level and most affordable option is to simply put the F-22, F-16 and F-15 back into production...upgraded to the extent affordable and work on a real deal 6th gen fighter.
USN & USMC carrier mission.
This one is obvious. The Advanced Super Hornet. Instead of a modest upgrade as is planned now we go full force. More powerful engines. Make it as stealthy as is possible. Take what widgets you can from the F-35 program. Consider a full hybrid force of Growler/Advanced Super Hornet Frankenstein models that combine the features of both aircraft to make your entire fleet capable of conducting electronic warfare, an area where the USN is the world leader and call it a day. An even easier solution would be to simply piggy back off Navy buys of the Advanced Super Hornet.
USMC.
Extremely simple. Follow the backup plan that saw the Marine Corps purchase British Harriers. Keep the AV-8B in service until 2030 and beyond. Purchase Advanced Super Hornets and position them with SPMAGTFs (they already deploy with KC-130's...putting F-18's in the mix shouldn't be hard) and forward deploy them to cover MEU's.
Brits and Allies.
The Brits will have the most heartburn among our allies to a possible cancellation of the F-35. The Dutch, Italians, Japanese, Australians, Canadians and others will almost smile that the heart wrenching and budget busting decision has been taken out of their hands.
They'll want refunds and that will be sticky...but it doesn't have to be. They'll need replacement aircraft and will probably follow the USN and USAF's lead on buying upgraded F-15 and 16's. Discounted pricing should make the financial ministry smile and lessen the pain while at the same time getting them an affordable option that matches US jets and planning.
But what about the Brit carriers?
Interesting issue. The Brits have a couple of options here. First they can piggy back off the USN and install electromagnetic launch systems on their ships or they can make them huge LHDs. Personally I believe that the Brit carrier mafia will want the capability to launch conventional aircraft. That means you're looking at either Super Hornets or Rafale's for the decks. I have no idea which way the wind blows in the UK on the issue.
The facts?
Its real simple. There is a way out. Is it pleasant? No. Is it pain free? Not at all. Does it stop the bleeding now? Definitely. All it takes is the will and the acknowledgement that a mistake was made and needs to be corrected.
Physical courage is easy. Moral courage is hard.
UPDATE: I did not consider another airplane that is currently available that is low cost, STOL capable and would truly get Marine Air headed back in the direction of an affordable AND capable part of the Marine Corps. The SAAB Gripen! If it is equipped with the same engines as the Super Hornet, if the same avionics are installed then we can have an extremely capable close air support with fighter capability we've always wanted. Then we turn our attention to developing more capable missiles and enhancing our electronic attack and all is right with the world again.