President-elect Donald Trump fired off a series of tweets early this morning, as he is wont to do, this time with one of them aimed at the F-35 Lightning II program. Over the years the has grown massively over-complicated and over-budget, but Trump hasn’t yet said what he wants to do about it—if he can do anything about it.

To his credit he’s right about the jet’s costs. Over the past few years it’s become the poster child for overblown military spending, a trillion-dollar money pit that . It’s received widespread criticism from within and outside of the military.

But unlike the tweet in which he yelled at his Amazon Alexa to “Cancel order!” on the next Air Force One, Trump isn’t exactly proscribing anything here. He’s not saying the F-35 program, with Lockheed Martin as the general contractor, will be canceled, just that the United States will save “billions of dollars.” Don’t worry about the specifics.

The problem with wanting to go ahead and start saving money on the F-35 now is that, for the most part, the time to speak up was 20 years ago. Much of the trail of its bloated cost can be found in its tortured development, which itself was borne out of a deeply strange requirement. The one F-35 platform was supposed to replace a bountiful variety of planes, ranging from the fast and light F-16 Viper, to the hovering AV-8B Harrier II, to the massively armored flying gun known as the A-10 Warthog.

It was, in short, an essentially impossible task that was somehow supposed to save everyone money in the long run. And even when it became blatantly obvious that this hodgepodge of competing requirements was never going to work properly, the defense establishment realized that such a massive program would be a lot harder to kill if its largesse could be spread across as many Congressional districts as possible.

The DoD painted the F-35's alternative jet engine as a huge unneeded expense, one that was more…

And as the cliché goes, we ended up with a jack of all trades and a master of none that somehow will cost over a trillion (a trillion!) dollars over the program’s lifetime.

But now that we have our weird dumb plane, one that can somewhat-stealthily take out ground targets, land on an aircraft carrier, and land vertically like a helicopter, we’re a bit beyond the point of saying “just cancel it.”

If we cancel it now, it’ll take at least a decade and hundreds of billions of dollars more to develop a whole new set of fighter jets from scratch, judging by the last 50 years of aircraft development. Which would have been fine 20 years ago, as I said, but the U.S. Air Force’s F-16s and A-10s, the U.S. Navy’s F/A-18s, and the U.S. Marine Corps’ F/A-18s and AV-8Bs are too old and too tired to last at least another decade, if not more.

And that’s a problem, if your long-term goal is to start

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So what’s Trump’s plan for the F-35? It’s not entirely clear, either from his tweet or from the standpoint of strategic planning. We may in fact be too far down the road—or in the air, I guess—with this thing to stop it now.

Lockheed Martin stock is as of this writing.