In August, when the White House and Congress failed to agree on taxes and spending, they compromised on what's called "sequester." That means an automatic 10 percent across-the-board cut in domestic spending and in the Pentagon, effective on the first day of next year. Defense Secretary Leon Panetta says that would be "a disaster" for the Pentagon. How much defense spending does the United States really need? How much can it reasonably afford? Will it really happen or will the White House and Congress kick the can down the road once again?