On average, it took 1,000 sorties of B-17 bombers dropping nearly two-and-a-half million pounds of “dumb” bombs to successfully knock out a significant Nazi target in 1944. By contrast, during the 2003 invasion of Iraq, a B-2 bomber could reliably achieve the same result with a single 2,000 pound “smart” bomb—and then go on to strike up to fifteen more targets in a single mission.

This level of accuracy proved to be an unprecedented and powerful force multiplier and was a central component of the so-called “second offset” strategy in the closing stages of the Cold War. By pushing the technological envelope, the U.S. and its allies could equalize the odds in any defense against the numerically superior Warsaw Pact in a hypothetical conflict. These same technologies were employed to deter aggression from smaller states by credibly holding the depth of their crucial command and logistic networks at risk, all while minimizing risks for civilians—a capability demonstrated in the Gulf War. The United States’ unique advantages in delivering precision strikes thus helped keep the peace in Europe and elsewhere while minimizing the number of American boots on the ground, quickly becoming a bedrock of U.S. combat and deterrence operations the world over.

Twelve years later, the story is very different. According to a  report released this summer by the Center of Strategic and Budgetary Assessment,  the U.S. monopoly on precision guided munitions (PGM) is ending. Even the Joint Chiefs of Staff admit that America’s traditional technological advantage is eroding. In the report, authors  Mark Gunzinger and Bryan Clark lay out the situation in depth, and propose a novel solution for turning the tables and regaining the upper hand. While the entire report is absolutely worth a read, it clocks in at over seventy pages and is packed with charts and technical data. Here is the run-down to get you up to speed on the problem—and the witty solution proposed by Gunzinger and Clark—in under ten minutes.

The Reemerging Salvo Competition:

From countless drone strikes to Operations Odyssey Dawn in Libya and Inherent Resolve today, pinpoint PGM strikes have been a hallmark of U.S. military action for over a decade. Now, potential American adversaries, from Iran and North Korea to Russia and China, have developed significant PGM capabilities of their own—and hordes of countermeasures to defeat American PGM. In any confrontation with these states, they could respond to U.S. strikes with smart bombs of their own. This would lead to what Gunzinger and Clark dub a “salvo competition,” in which the side that gains the upper hand in employing precision strikes will have a disproportionately large tactical advantage.

Gaining that advantage centers on altering what’s known as the Probability of Arrival (PA): the percentage chance that a given PGM will successfully strike its intended target. Gunzinger and Clark suggest that in planning an air campaign, enough ordinance should be allocated to ensure a given target is eliminated with 95 percent certainty.

Operating in uncontested airspace with stealth aircraft or standoff cruise missiles against opponents with weak or nonexistent air defenses, American PGMs have routinely achieved a PA bordering on 90 percent. Factoring in duds and mechanical issues, that B-2 with fifteen PGM would be able to conduct about ten successful strikes at 95 percent certainty of destruction by allocating three smart bombs for every two targets.

In a contested environment, near-peer competitors have a plethora of ways to drive the PA down. Kinetic defenses, from radar-directed close-in weapons systems to advanced surface-to-air missiles, like the S-300 currently being shipped to Iran from Russia, can intercept cruise missiles and potentially pose a threat to stealth aircraft. Electronic decoys and jammers can confuse or attract PGMs in order to prevent them from hitting their targets. Even if the enemy’s defenses can be overcome, their own PGMs could still attack and credibly degrade U.S. targeting networks, airbases, aircraft carriers, and other strike ships.

Gunzinger and Clark demonstrate how, by causing changes in the PA, these defenses have an exponential effect on the amount of PGMs that will need to be expended because of the desire to eliminate targets with 95 percent certainty. If the PA in Operation Iraqi Freedom hypothetically fell from 90 percent to 50 percent, it would have taken 149,250 PGM to strike the same 19,900 targets hit by the 27,800 smart and dumb munitions that were actually used.

Until the 2014 Quadrennial Defense Review, it remained standing U.S. policy for the military to be able to fight two major wars at once. Yet combating two Iraq-sized states at 50 percent PA would require almost 300,000 smart bombs, roughly equivalent to all the PGM procured by the Department of Defense since 2001. The U.S. would also have to increase the number of sorties generated by a factor of ten—assuming zero aircraft attrition—to carry out all these attacks in thirty days.

Will the Bomber Always Get Through?:

Considering the U.S. Air Force is operating with the smallest and oldest fleet of combat aircraft in its history, increasing sorties by that magnitude with current platforms is hard to imagine: enter the Air Force’s pitch for the Long Range Strike Bomber program. It’s an idea that’s generated controversy about the need for the program or long range strike at all. Considering the potential cost of these bombers (at a minimum, $550 million each), it’s worth musing on alternative platforms for strike.

Attacking targets solely with “long range standoff” PGMs like the Tomahawk is, according to Gunzinger and Clark, prohibitively expensive. The analysts observe that carrying out the 2003 strikes using hypothetical cruise missiles with a PA of 100 percent would have cost $22 billion dollars just to acquire the 18,700 missiles; again, approximately equal to the total outlays on PGMs since 2001. That sum is about 40 percent of the entire American outlay for the War in Iraq in 2003. In addition to their cost, these sorts of PGMs also have difficulty engaging hardened or mobile targets.  Cruise missiles simply can’t get on station fast enough or with enough payload. Their long, subsonic glide paths allow them to be tracked and intercepted relatively easily unless used en masse.

China, Russia and Iran have defenses that are not just a threat to slow cruise missiles. Their formidable (and growing) air defenses make attacks by conventional aircraft dropping direct attack PGM with ranges under 50 nautical miles (nm) seem suicidal. Even if next-gen tactical aircraft like the F-35 could use their stealth to penetrate the air defense bubble, they would probably not have the range to engage high value targets inland. Due to payload limitations and their inability to loiter because of fuel constraints and the air defense threat, they would also struggle to engage highly mobile targets. Even specialized sorties operating in uncontested environments like the Scud Hunts during the First Gulf War had trouble engaging, locating, and destroying targets such as transporter erector launchers (TEL).

That’s a problem, because Chinese-made TELs can set up and fire an anti-access area denial “carrier killer” missile before relocating in under ten minutes. Surface-to-surface missiles threaten the airbases, carriers, and amphibious assault ships that U.S. tactical aircraft need to operate from. Escort cruisers and destroyers can carry long range strike missiles, but because of the inability to reload at sea and the need to devote significant storage to air and missile defense ordinance, their magazine depth and the frequency of strikes are both sharply limited.

As Gunzinger and Clark note, future success in precision strike is directly correlated with the health of the stealth bomber force. There’s a need for stealthy platforms that can gain the element of surprise, and bombers have the ability to approach targets beyond the range of submarine based launchers and survive defensive fire that would deter surface ships or non-stealthy aircraft. Their global range allows them to strike from bases any enemy would be hard pressed to retaliate against. Yet constructing masses of stealth bombers isn’t feasible for the Pentagon, so ways to increase the efficiency—and survivability—of the force have to be found.

Reforming Operational Concepts-Increasing PA on the Cheap:

In an austere budget environment, the hunt for technological silver bullets must be accompanied by a reexamination of underlying operational concepts. At the core of this doctrinal reset is the idea that strike should predominantly be the realm of bomber aircraft, not fighter-bombers.

Due to current stealth bomber designs and the global network of American airbases and tanker aircraft, the United States has a considerable efficiency advantage in its ability to deliver more PGM than either Russia or China if strikes originate from more than 2,500 nm away from targets. Gunzinger and Clark note that the U.S. can deliver far more ordinance per pound of fuel used at these distances. From a survivability perspective, adversaries would be hard pressed to retaliate against bomber strikes at these ranges without going nuclear.

Within 2,500 nm, this efficiency advantage reverses. Inside that range band, ground launched cruise missiles can pound incoming amphibious forces or in–theater airbases with relative impunity. From a logistics standpoint, it’s much easier for a defender operating over their own airspace to generate sorties when compared to U.S. forces reliant on long and easily disrupted air or naval lines of communication. Potential adversaries could bring almost all their forces to bear, as opposed to the pittance of their forces that could operate 2,500nm from their bases and reliably hit targets.