History may one day judge the global economic crisis as the turning point that finally forced Washington to confront the runaway monster of military spending.

On Thursday, U.S. Defence Secretary Leon Panetta is to spell out the details of an estimated $450 billion in military cuts.

At the same time, the Pentagon also fears it is expected to lose up to another $500 billion over this decade as its share of a second round of across-the-board cuts to reduce the overall federal deficit.

That would represent close to $1 trillion in reduced military spending over the next 10 or 12 years.

The numbers are so large that it is almost impossible to grasp the magnitude of trying to control the greatest defence budget of the modern age.

But these efforts are based on a stark realization that even America can no longer afford a military budget that has shot up 73 per cent more than it was in 2001 in real terms, and which consumes a full 20 per cent of U.S. federal spending.

One war at a time

At this juncture, the term "runaway spending" is entirely justified. The U.S. today is laying out roughly $100 billion a year more in real, inflation-adjusted dollars on defence than it did even at the scariest heights of the Cold War.

The Nimitz-class USS Carl Vinson aircraft carrier, one of very few its size in the world, taking part in a naval exercise with the Royal Malaysian Navy in 2011. (Reuters)

But with reality setting in, this Pentagon seems about to concede — for the first time in three generations — that it is prepared to give up its famous, often boasted about capacity to wage two wars abroad at once, such as it has been doing in Iraq and Afghanistan.

Still, the U.S. will certainly remain the mightiest military force on the planet over the foreseeable decades. But it will undoubtedly have to pick its opponents far less haphazardly than in the past.

It will also probably want to avoid large land wars anytime soon, given the strong domestic anger over the prolonged post-9/11 combat in Iraq and Afghanistan.

A Pew Poll in June found that 60 per cent of Americans blamed those conflicts for "a great deal" of U.S. indebtedness and suffering.

Defence has even emerged as a surprise target in parts of the highly conservative Republican primaries, where libertarian Ron Paul has made inroads while preaching a "bring home all the troops" isolationism.

Strategy for the 'silver seas'

Even where Republicans and Democrats cannot agree on specific cuts — and surely won't in a presidential election year —there appears to be a general consensus that the military's willingness to serve everywhere no longer meets U.S. national interests, especially its economic ones.

Over the past year, the White House and Pentagon have refocused American military strategy around the Pacific and Indian Oceans, as China becomes the centre of concern, along with North Korea, Pakistan, and Iran.

It clearly looks like a "strategy for the silver seas," as the British used to call oceanic priorities, while concentrating on ships and aircraft and much less on ground troops.

In the Pacific and Indian oceans, the U.S. is already building new training and patrol alliances with Japan, South Korea, the Philippines, Malaysia, Indonesia, India and Australia (where it is also establishing a marine base).

Expect Canada to receive pressing invites to join in these multilateral patrols.

Base closings?

With the war in Iraq ended, at least as far as the U.S. is concerned, and Afghanistan winding down, Washington plans to cut its army and marines by at least 90,000, bringing ground capability back toward 520,000, or close to what it was at 9/11.

Reductions, however, are unlikely to stop there as personnel costs, including salaries and benefits, amount to almost $181 billion annually, fully one-third of the Pentagon's base budget.

These cuts would likely be deeper still if unemployment was not so high and military bases were not so overwhelmingly concentrated in politically powerful southern states.

As a result, we should expect to see Panetta cut or delay large procurement projects and new systems first, rather than reduce troop numbers immediately.

Arms lobbyists, Republican presidential hopefuls, and Washington's always relentlessly military-friendly think-tanks will fight fiercely to slow the retreat. But so long as all Washington's budget battles are as intense as they have been, the military will be in the crosshairs.

Even the most excitable flag-wavers are having a harder time justifying overall defence spending that is six times that of China, and a dozen times higher than Russia's.

There is nothing on the planet remotely like the 11 massive U.S. aircraft carrier groups. China has one such, relatively small carrier group. In fact, the U.S. navy outranks the next 13 world navies combined.

If you count up all the military spending in the world today, the U.S. accounts for 43 per cent of the total.

Howls of rage

What will make a sensible size for a future U.S. military? That will always be a heated debate in that country.

Although most Americans have had little direct involvement with military service since the draft was ended almost 40 years ago, those who do wear the uniform — and who come increasingly from military families — are regarded with extraordinary reverence.

At the same time, American has become ever more obsessed with national security.

Though as Todd Purdum, Vanity Fair's political editor argued in the latest edition, such a fixation "has resulted in correspondingly less attention to almost every other social, political, and economic challenge we face, from public education to the environment, from health care to energy — as if these were not themselves matters of national security."

Some defence analysts are anticipating howls of protest over these impending cuts and that the blame will fall fiercely on President Barack Obama's shoulders.

In normal years, such cuts would be strangled before birth inside Washington's defence-coddled beltway.

But these are not normal times and it seems possible now that the American public is truly irritated enough to demand rational reform even from its generals.