U.S. military spending stands at record highs and keeps growing, although the country's once long list of enemies has shortened.

Indeed, the Cold War ended nearly two decades ago and U.S. forces are scaling down presence in Iraq and Afghanistan. Then why the U.S. defense spending keeps growing?

Record-high spending

Yet U.S. President Barack Obama on Monday requested congressional approval for 708 billion dollars in defense spending -- a record-high amount some analysts said was not only for the nation's defense but also for global dominance.

"American policymakers want the ability to intervene anywhere in the world," said Douglass Bandow, fellow at the libertarian CATO institute and outspoken critic of high military spending. "(But) America can no longer afford to play globocop."

"Offense is far more expensive than defense," he said, explaining that heightened defense spending reflects Washington's view of itself as a force for global stability.

The president's request included a 3.4-percent boost in the Pentagon's base budget and 159 billion dollars for U.S. missions in Afghanistan, Iraq and Pakistan.

The defense department said the funds are needed for a variety of costs from health care to missiles.

"This funding increase allows the DOD (Department of Defense) to address its highest priorities, such as the president's commitment to reform defense acquisition, develop a ballistic missile defense system that addresses modern threats, and continue to provide high quality healthcare to wounded service members," the department said in a statement.

Mackenzie Eaglen, fellow at the conservative Heritage Foundation, said the spending is in line with U.S. objectives since 1945 -- taking an active global role to anticipate and manage threats, protect freedom, and prevent global conflict.

"The ability of the United States to reassure friends, deter competitors, coerce belligerent states, and defeat enemies does not rest on the strength of our political leaders' commitment to diplomacy," she said. "But rather, it rests on the foundation of a powerful military."

Costs have risen substantially

But some said the costs of that strength have risen substantially.

Carl Conetta at the liberal-leaning Project on Defense Alternatives at the Commonwealth Institute, contended that U.S. defense spending has risen significantly higher than the Cold War average.

Measured in 2010 dollars, average Defense Department budgets were 423 billion dollars between 1954 and 2001 --more than two-thirds less than Obama's request, he wrote in a report titled "An Undisciplined Defense: Understanding the 2-trillion-dollar Surge in U.S. Defense Spending."