Doing a quick look through some articles on the aborted Crusader Self-Propelled Howitzer. The idea started in 1994 to replace the M-109 155mm Paladin SPH. What came out was a tracked gun with attached support trailer that weighed as much as one M-1A2 Abrams tank. By May 8, 2002 when the program was cancelled, it had consumed $2billion and not even a prototype vehicle had been produced.
Because of its massive weight, it would take 64 C-17 Globemaster IIIs to airlift 18 Crusaders. I must point out that the USAF is only buying 180 C-17s, so to move one artillery battalion by air would take up 1/3rd of the entire C-17 fleet. That was given as one reason why Crusader was cancelled, it could only travel by ship to be deployed efficiently.
Another reason is the rise in the use of precision weapons on the battlefield. In Afghanistan roughly 65% of the ordinance dropped was of the 'smart' category. When USAF Combat Controllers or Green Berets operating with Northern Alliance forces can call up a B-52 launched from the US and armed with JDAMs, is there a need for self-propelled artillery? Obviously not. What if the US and its allies don't have air superiority? Crusader would be easy pickings for enemy air so this is not a valid argument for the purchase of Crusader.
But Crusader was looking to be an $11billion project for the Army as they planned to buy 840+ Crusaders and 840+ trailers. Factor in the eight year gestation period before cancellation with a 2006 planned introduction, Crusader had built up a cadre of people with vested interests in it being deployed.
So when Secretary of Defense Donald Rumsfeld starts looking to make the military more mobile to meet President Bush's goals and the 19-ton Stryker wheeled armored vehicle entering Army service leading the way, the massiveness of the Crusader becomes obvious. And on May 8th, 2002, Secretary Rumsfeld cancelled the Crusader program and redirected the FY2003 unspent Crusader funds to other transformation objectives like the Excalibur precision artillery shell. And there was a backlash when an unauthorized talking point memo critical of canceling Crusader and long on being scary made into Congressional hands, bypassing Secretary of the Army White and Secretary of Defense Rumsfeld. The leaker came out of the Army's Office of Congressional Legislative Liaison[OCLL], Kenneth Steadmen, principle deputy of the OCLL, accepted responsibility for the memo and resigned.
This kind of political in-fighting over military funding is not new. Though usually it is intra-service in nature as the aborted Revolt of the Admirals was. The Revolt of the Admirals happened when the USAF was trying to get funding for B-36 nuclear armed bombers from Congress at the same time the US Navy was trying to get more funding for its first super aircraft carrier. So the Navy leaked to Congress information showing how vulnerable the B-36 was. Well it backfired on the Navy. The USAF got its B-36s and the US Navy had to scrap the keel of its first super carrier.
The Pentagon needs reform. Whether Rumsfeld can toss out the Princes and their little fiefdoms I don't know. But if he fails, then expect another Crusader project to show up or the A-12 Avenger program that sucked massive amounts of money out of Naval Aviation before crashing. All the while we would still be fighting the War on Terror.