$1.5 billion of your tax dollars, burning in close formation: smoke pours from Saturday’s B-2 crash at Andersen AFB, Guam.

Prospects for a new, manned bomber went down in flames (quite literally) with Saturday’s crash of a B-2 at Andersen AFB, Guam. . While both pilots ejected safely, the crash reduces the B-2 inventory to only 20 aircraft. Further losses—considered all-but-inevitable in any military aviation program—will place additional constraints on the nation’s B-2 fleet, and potentially limit employment options in a major conflict with China, or a resurgent Russia.

Admittedly, the remaining B-2s are still a potent striking force. The “Spirit” is the most powerful bomber in aviation history, with a combination of range, stealth and precision-strike capabilities that allow it to travel vast distances, penetrate dense air defenses and deliver weapons with pin-point accuracy. B-2s played a major role in the early phases of bombing campaigns against Serbia, Afghanistan and Iraq. They would represent a critical element of any U.S. effort to target nuclear facilities in Iran.

While the Air Force still has enough B-2s for most scenarios, the Guam crash highlights the dilemma facing military planners. Key elements of various war plans are built around a small number of strategic assets, with decreasing margins for combat losses, or non-availability for other reasons. The U.S. Navy, which one commissioned 24 aircraft carriers of a single type, now has only twelve carriers in all–and that number will drop to eleven with the projected retirement of the USS Kitty Hawk.

Our bomber fleet has experienced a similar decline. Today, the Air Force has a total of 171 heavy bombers (67 B-1s, 20 B-2s, and 94 B-52s). While that sounds impressive—and today’s models are vastly more capable than their predecessors—its worth remembering that the USAF once purchased 744 B-52s and more than 2,000 B-47s.

Ah, for the good ol’ days when a strategic bomber could be purchased for roughly one-tenth the cost of an F-22. But, with B-2s priced at $1.5 billion each, and $300 million for a single B-1, we’ll never see a return of the massive bomber units of the 1950s. But it’s equally apparent that the Pentagon can no longer afford relatively small numbers of strategic bombers, no matter how matter how stealthy or precise they might be.

That’s one reason the lost B-2 (nicknamed the Spirit of Kansas) won’t be replaced, and the Pentagon has resisted Northrop-Grumman’s offer to reopen the assembly line. With the Air Force scrambling to finance the JSF, KC-X and CSAR-X programs (to name a few), building more B-2s makes no fiscal sense whatsoever.

Which brings us to the service’s plans for its next-generation bomber, set to appear sometime toward the end of the next decade. As we noted a few months back, the Air Force has asked prospective contractors to develop manned and unmanned versions of the new aircraft. Taking crew members out of the cockpit would save billions in training and personnel costs, while retaining the most desired features of the new platform—range, precision and stealth. That would allow the USAF to buy more UAV bombers, at a substantially lower unit cost.

That’s why the young men and women flying today’s Buffs, Lancers and Spirits may go down as the last bomber crews. Despite their consummate flying skills (including an admirable safety record), there are limits to what the Pentagon can afford, even in an era of $500 billion defense budgets. The sudden loss of a single, billion-dollar aircraft was a sobering moment for the Air Force and defense planners.

In the span of a few seconds on Guam–the time required for the B-2 crew ejected from their stricken aircraft–$1.5 billion in state-of-the-art defense technology became nothing more than expensive debris, and a UAV emerged as the leading candidate for our next long-range bomber.

The era of manned bombers, which began almost a century ago, isn’t over yet. The venerable B-52 is expected to soldier on past 2030, long after current crew members have retired. B-2s and B-1s will also remain a part of our military calculus for years to come.

But the handwriting–or more correctly, the fiscal analysis–is already on the wall. Last Saturday’s B-2 crash may didn’t mark the end of manned bombers, but it may represent the beginning of the end.

By andrei