(CBS News) WASHINGTON -- There is a much bigger Washington fiscal crisis coming in three weeks, when automatic, across-the-board budget cuts go into effect unless Congress finds another way. In Washington lingo, the budget cuts are called sequestration, and they're already cutting into national defense.
Watch: Scott Pelley speaks with President Barack Obama about sequestration, at left.
Late Wednesday afternoon, the 5,000 crew members of the aircraft carrier Truman got the word: they will not be leaving their home port of Norfolk, Va., for the Persian Gulf this Friday, as planned.
Their deployment is being postponed due to the looming budget crisis. Vice Admiral Mark Fox says that means the U.S. will have only one -- instead of the normal two -- aircraft carriers in the Persian Gulf.
"What it does change is the opportunity to have additional capability immediately," Fox says. "There will be additional time, distance associated with bringing another vessel over if that's required."
Fox says the move will save "in the hundreds of millions of dollars."
The postponement of the Truman's deployment -- along with that of a guided missile cruiser -- is the most visible effect of the threat of automatic budget cuts, known as sequestration, compounded by the absence of a new budget for fiscal year 2013. It's a double-whammy which has a normally affable Defense Secretary Leon Panetta hot under the collar.
"This is not a game," he declared Wednesday in a farewell speech at Georgetown University. "This is reality."
If sequestration takes effect at the beginning of March, Panetta says the Department of Defense will have to cut $46 billion in the remaining seven months of the fiscal year.
"We will furlough as many as 800,000 D.O.D. civilians around the country for up to 22 days," he said Wednesday. "They could face a 20 percent cut in their salary. You don't think that's going to impact on our economy?"
The cuts will not affect combat operations in Afghanistan. But troops in the field would take a hit in the pocket. A planned pay raise could be cut nearly in half.