Amid growing tensions with North Korea, the United States Air Force has deployed three B-2 Spirit stealth bombers to Guam - the nearest U.S. base to the Peninsula capable of hosting the high maintenance bombers. The deployment represents over 15% of the entire B-2 fleet. Approximately 200 airmen have been deployed to Guam in support of the "Pacific Command's Bomber Assurance and Deterrence mission." The B-2 notably cannot be deployed outside U.S. territory due to its delicacy relative to other U.S. platforms, requiring specialised weather controller hangers capable of accommodating the bomber's 52 meter wingspan. It's maintenance needs mean it can fly a sortie less than once a month assuming sorties of six hours or more - highly conservative for the long ranged and low speed bomber designed to fly for over 20 hours at a time. The bomber requires almost 120 hours of maintenance per hour of flight, and spends the vast majority of the time grounded. A single B-2 costs $135,000 per hour to fly as a result, and incurs maintenance costs of $3.4 million per month. The B-2's radar evading capabilities were designed to be the most advanced in U.S. service, eclipsing even those of the F-22 Raptor. Stealth aside, the B-2 is a subsonic platform with no anti aircraft weapons designed for operations without fighter support, to avoid the fighters giving away its position to enemy radars. This makes the Sprit bomber vulnerable to even older North Korean SAM and fighter platforms should its stealth be compromised or should its adversaries detect it visually or using infrared systems. With an extremely high concentration both of Radars and of SAMs north of the 38th parallel, and with the B-2 relying heavily on technology developed in the 1990s, chances that the platform would be detected and neutralised by North Korean air or air defence forces are high. This is a particularly serious issue considering flaws revealed in the Sprit bomber's radar evading capabilities.North Korea's military has long developed advanced anti stealth technologies, and has entered into high level air defence cooperation with Russia under which it was likely that further anti stealth technologies were transferred. It is also notable that both China and Russia have deployed extensive air defences with effective anti stealth capabilities to the North Korean border, with coverage extending well beyond the Korean Peninsula. These systems also pose a significant risk to the U.S. Air Force should it attempt to launch strikes, with both of North Korea's superpower neighbours having indicated that they would take measures to protect the country and would not tolerate attacks against the small country.The primary weakness of the B-2, which makes it somewhat unsuitable for sorties against North Korea from Guam, is that it spends over 99% of the time grounded and is extremely limited in the facilities from which it can deploy. With Guam well in range of North Korean missiles, including the Pukkuksong-2, Musudan and Hwasong-12, 13, 14 and 15 among others - all platforms capable of carrying nuclear, chemical or conventional payloads, the bombers at Andersen Air Force base represent a ludicrous target. With B-2 bombers costing over $2 billion dollars each, and with only 19 service and no possibility of future production for replacement, the platform is both highly valuable and irreplaceable. While the bombers would be safer launching sorties from the U.S. mainland, still well within range of the Korean Peninsula for the long range platforms, deploying from Guam increases their sortie rate at the expense of leaving them vulnerable. A missile strike destroying the multi billion dollar bombers on the ground on a U.S. territory would be a significant victory for North Korea's missile forces - a highly likely outcome should war break out particularly considering both the size and sophistication of the Korean missile arsenal and the recent demonstrated failings of U.S. air defence systems at intercepting ballistic missiles.