As the Pentagon prepares for the formal release its budget next week, there is much talk within the department that the $600 billion-plus that is likely to be proposed is inadequate. In fact, rooting out billions of dollars of waste in the Pentagon budget would leave more than enough to provide a robust defense of the country without increasing spending.

Waste at the Pentagon is nothing new. But recent revelations suggest that it may be reaching historic levels.

The Special Inspector General for Afghan Reconstruction has uncovered scandal after scandal involving U.S. aid to that country, including the creation of private villas for a small number of personnel working for a Pentagon economic development initiative and a series of costly facilities that were never or barely used. An analysis by ProPublica puts the price tag for wasteful and misguided expenditures in Afghanistan at $17 billion, a figure that is higher than the GDP of 80 nations.

Sen. Charles Grassley, R-Iowa, has called for a full audit of the unit responsible for the most egregious Afghan cases. And on Jan. 20th, the Senate Armed Services Readiness Subcommittee held hearings on the subject. The Pentagon's witness, Principal Deputy Undersecretary of Defense for Policy Brian McKeon, was decidedly on the defensive as senators from both parties peppered him with questions about his department's poor record keeping and lack of accountability.

It's not just about Afghanistan, though. Back in the United States, wasteful spending abounds. A Politico report on the Pentagon's $44 billion Defense Logistics Agency notes that it spent over $7 billion on unneeded equipment. Meanwhile, Congress is doing its part by inserting its own pet projects into the budget, whether or not they are top priorities in terms of defense needs. The most notable example is the F-35 combat aircraft, which at $1.4 trillion over its lifetime is the most expensive weapons project ever undertaken by the Pentagon. Despite the fact that the plane is far from ready for prime time, Congress stuffed 11 additional F-35s into the defense bill that was signed by the president last month.

These examples of waste and abuse spark memories of past Pentagon spending binges.

In the 1960s, Pentagon whistleblower Ernest Fitzgerald exposed $2 billion in cost overruns on Lockheed's massive C-5A transport aircraft, a fact that the Air Force had doggedly attempted to hide from the public. At the time it was one of the largest known examples of overspending on a weapons program. But the C-5 scandal pales in comparison with the likely cost overruns on the F-35 program or on the Pentagon's proposed $1 trillion in spending on new bombers, ballistic missile submarines and land-based nuclear missiles.

During the Reagan military buildup of the 1980s, tales of $600 toilet seats and $7,600 coffee makers convinced Congress and the public that the Pentagon had more money than it knew what to do with, and that the time to curb spending had come. But overspending on routine items – such as the Army's recent expenditure of $8,000 on a gear worth $500 – continues. In fact, because the Pentagon can't pass an audit, the department doesn't even know for sure how much it is overpaying on basic items, or how much excess equipment it is purchasing.

The common thread uniting the C-5 scandal of the 1960s, the spare parts scandal of the 1980s and today's array of wasteful expenditures is that they all came on the heels of major military buildups. When there is too much money to go around and no one is minding the store, spending discipline goes out the window. As then Pentagon procurement chief Ashton Carter said in a 2011 hearing, in the decade of increasing Pentagon budgets that kicked off the 2000s, it was always possible to reach for more money, "so it's natural that some fat crept into all of our activities during that time period."

What can be done to get the "fat" out of Pentagon spending? For starters, the department needs financial incentives to get its books in order. Members of Congress ranging from Ron Wyden, D-Ore., to Ted Cruz, R-Texas, in the Senate, and from Barbara Lee, D-Calif., to Michael Burgess, R-Texas, in the House have put forward bills designed to press the Pentagon to become audit ready as soon as possible.