The consequences could be felt most critically in the Pacific. Proliferating the F-35 among America's Pacific partners — traditional allies like Japan, South Korea, and Singapore — and potential new ones such as India — is a sine qua non of any meaningful military retrenchment in the region. But already Australia, arguably our closest ally, is on the verge of backing out. The Aussies had agreed to buy at least 100 F-35's. A Pacific "pivot" without the Lightning would be a fizzle.

The F-35's reliance on international partners should be a strength. It affords interoperability, giving the United States a platform around which it can build an international coalition capable of global reach. The Joint Strike Fighter’s inclusion of Italy and other partner-nations should also be a boon to the U.S. defense industrial base, whose future is tied to the F-35 project. Further, the program’s economics favor international purchases, balancing capital costs over more airframes, which also offers the advantage of greater allied power. All of these potential benefits, however, turn on a question of political commitment in the United States. In an environment where the Defense Department is increasingly the bill-payer for domestic, social programs, the F-35 has become a tempting target, and, with the specter of sequestration in sight, there may be more F-35 acquisition “extensions” in store.

But there's more bad news in the Italian decision. Italy has been a stalwart proponent of the jump jet "B" version of the F-35 that is also critical for future capabilities for the U.S. Marine Corps. Indeed, Italian aircraft carriers are essentially the same size as Marine amphibious ships.  For the moment, it is unclear how Italy intends to apportion its cuts — like the Marines, their carriers will be of little use without an airplane — but if cost is the sole driver, Rome will be tempted to go exclusively with the cheaper F-35A and perhaps mothball one of its carriers entirely.  The British have already backed out of their F-35B commitment, even though they have yet to kill the two carriers they've been building in anticipation. The British think they can squeeze a catapult on their small carriers to accommodate the U.S. Navy's version of the F-35, designated the "C" model, but it remains to be seen if the engineering makes any sense or is worth the cost. Israel and Singapore, as well as other Asian allies whose airfields are now threatened by Chinese ballistic and cruise missiles, were also intrigued by the jump-jet F-35, but a rise in price is inevitable and will be discouraging.

Indeed, the fate of the F-35 program is as good an indicator of the depth and breadth of Barack Obama's retreat from U.S. military preeminence. If more international partners on the project start bailing or similarly "extending" their F-35 plans, the pace of American and allied decline will accelerate.