CBS News National security Correspondent David Martin reports the fate of the Crusader Artillery System has also suddenly become a test case of Rumsfeld's ability to transform the American military.
Without mentioning names, Rumsfeld said he was looking into reports that Army officials had gone behind his back to Congress in hopes of building political pressure to rescue the project.
"I have a minimum of high regard for that kind of behavior," Rumsfeld told reporters.
Rumsfeld's comment about behind-the-scenes maneuvering over the future of the artillery project suggested he felt his authority as the Pentagon's top civilian official was being challenged.
It also raised questions about White's future. He is under political pressure as a result of his contacts with Enron Corp. officials during the company's collapse last year. White had headed Enron Energy Services, a subsidiary, before he became Army secretary.
The Army's Inspector General was ordered to investigate the back door lobbying, but one Senate supporter of the Crusader project defended White.
"I think that's very unfair to Secretary White to accuse him of lobbying on the Hill," said Sen. James Inhofe, R-Okla.
Loren Thompson, a defense expert at the Lexington Institute, a think tank, said the flap over Crusader may well be the final straw for White, a decorated Vietnam veteran.
"Mr. White has finally found a matter of principle on which to depart," Thompson said in an interview.
Col. Tom Begines, an Army spokesman, said he had no comment on the matter.
The conflict over Crusader is part of a wider battle Rumsfeld has waged with the Army and other services since he took office last year and pledged to transform the military to meet 21st century challenges.
In a related development, the Pentagon's top weapons buyer said there no longer is any question of canceling the Air Force's F-22 new-generation stealth fighter. Pete Aldridge, the undersecretary of defense for acquisition, said the only question is whether the Pentagon will buy all 339 planes the Air Force says it needs. Some in the Pentagon believe fewer than 200 are needed.
Aldridge also announced that the Marine Corps will resume flight testing of its innovative but highly controversial V-22 Osprey. The hybrid helicopter-airplane was grounded in December 2000 after two crashes killed 23 Marines and raised tough questions about the aircraft's aerodynamics.
Rumsfeld has called into question the future of several major weapons programs, although canceling the Crusader would be the biggest and boldest move so far in his campaign to force change. Of the program's projected total cost of $11 billion, about $9 billion has yet to be invested.
"Crusader now becomes a symbol of whether Rumsfeld's priorities will prevail or not," Thompson said.
The Army considers the Crusader vital to its strategy for modernizing U.S. land forces and transforming them to a lighter, more mobile force. The Crusader is a 155mm self-propelled howitzer that has undergone initial tests of its firing capabilities and is scheduled to enter service in 2008.
Rumsfeld said he was told Wednesday that his aides had instructed White to produce a study by the end of May on alternatives to Crusader — "that would assume that Crusader was canceled." Once the study's results were in hand, a final decision on Crusader would be made, he said.
"It clearly suggests that that's the intention — to cancel it," Rumsfeld said.
Rumsfeld seemed disturbed by reports that the Army's office of legislative affairs had sought to fight the planned cancellation by preparing "talking points" for members of Congress to lobby for Crusader.
Asked by a reporter whether he believed that Army leaders were fighting a rearguard action against him, Rumsfeld said Deputy Defense Secretary Paul Wolfowitz was looking into that.
Rumsfeld made clear, however, that he expects Army leaders to fall in line once he makes decisions.
"Are you talking about every single human being in the Army is going to behave himself or herself? Not likely," he said. "Ought a president and a secretary of defense and a deputy secretary of defense be able to expect that the leadership ... will in fact be supportive once a decision is made? Of course."
In a separate session with reporters, Aldridge, the Pentagon's chief weapons buyer, said the Army should "let the secretary make up his mind as to what are the priorities for this department."
"To be on the Hill lobbying for a different approach I think is probably not appropriate," he added.
Crusader is being developed by United Defense Industries Inc., a defense contractor controlled by the Carlyle Group, an investment firm led by Frank C. Carlucci, a former secretary of defense.