The Pentagon has issued a warning: the major cuts to the military that President Obama proposed in his speech on spending are going to come with a heavy price. Reuters reports:

The United States may have to scrap some military missions and trim troop levels if President Barack Obama sticks with his goal of saving $400 billion on security spending over a 10-year period, the Pentagon said on Wednesday. …

“It’s not just a math exercise which is ‘cut $400 billion’,” said Geoff Morrell, the Pentagon press secretary. “It’s ‘let’s review our roles and our missions and see what we can forgo, or pare down, in this age of fiscal constraint, where we are all collectively trying to work with the deficit problem.'”

The cuts come to a military that has already been paring back forces. More from Reuters:

Defense Secretary Robert Gates already had eliminated or scaled back more than 20 troubled or “excess” weapons programs since April 2009. Last June he ordered the military to come up with more than $100 billion in overhead savings over five years, which could be reinvested in higher priority programs.

The core Pentagon budget is now about $530 billion, roughly $10 billion less than Gates said was critical when the Obama administration sent Congress its spending plan for 2012.

The Heritage Foundation’s Mackenzie Eaglen says cutting the military without considering America’s national security needs is a recipe for disaster:

Slashing defense spending without any changes–specifically reductions–in U.S. foreign policy commitments around the world is not only dangerous but more costly in the long run than maintaining stable defense budgets.

A review of roles and missions will not change U.S. foreign policy, only the President can do that. Starving the military as part of a deficit reduction plan may end up costing taxpayers more in the future if it makes the country less safe and increases the risk of another terrorist attack or the likelihood of drawing U.S. forces into yet another overseas mission.