President Barack Obama said today that it’s time to slow the growth of defense spending as the wars in Iraq and Afghanistan wind down, and he outlined a plan to slice $487 billion over a decade.

“The tide of war is receding,” Obama said, speaking at the Pentagon flanked by the nation’s top military brass. “We have the opportunity and the responsibility to look ahead to the force that we will need in the future.”

The military will be leaner but maintain its superiority and agility, he said. He also said defense spending would still increase, although more slowly, and would continue to be higher than the next 10 countries combined.

Obama said the new strategy would continue to shift from Cold War-era priorities to a focus on intelligence and counterterrorism. And he said the strategy would beef up the nation’s focus on potential threats in Asia and maintain vigilance in the Middle East.

Obama pledged to ensure that the nation not cut too deeply. “We can’t afford to repeat the mistakes we made in the past … when our military was left ill prepared for the future,” he said.

The belt-tightening largely follows the cuts mandated by last year’s bipartisan Budget Control Act. Cuts of about $450 billion are mandated by last year’s Budget Control Act, not including an additional $600 billion in automatic defense cuts that are set to take effect starting Jan. 1, 2013, if Congress does not act. That sequester was triggered by the failure of the super committee to reach a deficit reduction deal last year.

The president’s announcement today is likely to come under strong criticism from some Republicans, including former Massachusetts Gov. Mitt Romney, who has proposed increasing the size of the military as part of his presidential campaign platform.

And the details of the cuts are sure to set up a massive struggle in Congress as defense contractors and Members seek to protect programs facing the ax.

Defense Secretary Leon Panetta argued for a smaller, well-equipped force instead of a larger one whose support has been cut across the board.

Panetta said the Army and Marine Corps no longer need to be as large with the war over in Iraq and winding down in Afghanistan. But the military overall will continue to invest in new capabilities and be able to execute missions “across the spectrum.”

Panetta said that “in many ways we are at a crisis point” fiscally, but said with crisis comes “opportunity” to look at things differently.