"Psst! Buddy! Buy this engine -- it's better than the other guy's."

No. It isn't.

"OK, well, how about you buy our engine and the other guy's? Ours is just as good."

No. We don't want it.

"OK, OK. Here's my final offer. Don't buy it now. We'll build the engine for free, and you can decide later. That's fair, right?"

No ... thanks?

So far, General Electric (NYSE: GE) has been shot down at every turn. Every time it suggests the Pentagon buy its F136 fighter jet engine for the Lockheed Martin (NYSE: LMT) F-35, the answer's the same: "No." The Pentagon's perfectly happy with the engine it already has, built by United Technologies (NYSE: UTX). Now, in a desperate, last-ditch attempt, GE is making its last and final offer -- to build its alternative engine for free, in hopes the Pentagon might one day change its mind.

At an estimated $100 million annual cost-to-develop, GE's making an expensive and risky gamble -- but this time it just might pay off. The chairman of the House Armed Services Committee says he sees nothing wrong with giving GE access to its research and testing facilities, so that GE can continue developing the F136. And while the Air Force seems unlikely to change its mind on outfitting the F-35 with GE's engine, USAF isn't the only game in town.

Over the 60 years that pundits predict the F-35 will be in service, the plane is expected to sell literally thousands of copies globally. Britain, Italy, Canada -- any of the eight nations co-developing the F-35 with Lockheed might want to outfit their planes with GE's engine. Especially Britain. Remember that GE is co-developing the F136 with Rolls Royce ...

And that's just the beginning. Who's to say that the F136 wouldn't work just as well if tweaked to power warplanes from Boeing (NYSE: BA)? Or Northrop Grumman (NYSE: NOC), EADS, or Dassault, for that matter?

Foolish takeaway
So make no mistake, GE isn't making this offer out of the goodness of its heart. Still, it's offering the Pentagon a chance to keep an alternative in case, as GE has warned, UTX one day raises the price of its engine. And it's offering to do this at no cost to the U.S. taxpayer.

Pentagon, take note: The correct answer to this proposal is not "No, thanks" -- but simply: "Thanks."

Will GE finally move from "no" to "yes?" Add it to your Fool Watchlist, and find out.