Howard P. “Buck” McKeon, a Republican from California, is chairman of the House Armed Services Committee.

After no hearings and no input from Congress, President Obama unveiled a new strategy last week that unilaterally changed long-standing bipartisan defense policy. As he spoke, flanked by Defense Secretary Leon Panetta and a host of military brass, some of the president’s language may have sounded familiar.

A year ago Britain, our predecessor superpower, announced sweeping defense cuts that have reduced its military to a shadow of its former capability.

I do not seek to criticize our British friends, a critical ally; they are working hard to do what’s best for their citizens. But it is instructive to listen to the way British leaders sold their military reductions to citizens. When it came time to make significant defense cuts, downsizing that can only accurately be described as immense, London salved the wound with such efficacy that it was plagiarized by the Obama administration.

The British Strategic Defense and Security Review cut the Royal Air Force’s fighter force to around 200 planes. Forty percent of the British army’s tanks are being put in storage. The Royal Navy combat fleet has been whittled down to about the same size as the task force formed for the Falklands War with Argentina 30 years ago. The joke goes that today’s Royal Navy has more admirals than warships.

Prime Minister David Cameron’s justification for the broad reductions was “this is not simply a cost-saving exercise to get to grips with the biggest budget deficit in postwar history; it is about taking the right decisions to protect our national security in the years ahead.”

In unveiling the review, Cameron said that, despite the reductions, Britain would continue to provide “the most professional and flexible modern forces in the world,” vigilant against “all possible threats.” A year later, President Obama said our armed forces would be “agile, flexible, and ready for a full range of contingencies and operations.”

Both emphasized balance between domestic and defense spending. The British said that bringing the “defense budget back to balance is a vital part of how we tackle the deficit and protect this country’s national security.” Obama said that “it’s time to restore that balance” among national programs.

Both made attempts to justify additional risk incurred by reducing forces by retaining the capacity to reverse defense spending cuts. Cameron pledged that Britain would be able to “regenerate” capabilities gutted in the cutbacks. Obama’s review promised “reversibility” to mitigate “shocks or evolutions.”

Both strategic reviews emphasized capabilities that would be retained but were light on what capabilities would be lost. Both advocated the theory that national interests could be advanced through a drastically reduced military, yet neither explained how that works operationally.

I am not interested in questioning British strategy, but I have no qualms about critiquing our president’s claim that massive defense cuts somehow bring balance to our national programs. Defense counts for less than 20 percent of the federal budget but totals more than 50 percent of our deficit-reduction efforts, while domestic spending has exploded. No one is discussing lighter or more agile entitlement programs.

A smaller force may sound synonymous with greater flexibility and agility. But realistically, downgrading our force will only harm our ability to respond to unforeseen crises. Does having fewer Navy warships increase our flexibility to respond in multiple theaters? Does having fewer Air Force transport aircraft grant us greater agility to respond to an unforeseen contingency, such as last year’s earthquake in Japan or operations over Libya?

Advocates often claim that a smaller military is a “smarter” military. This is fallacious. A smarter military is a force tailored to threats — one that provides an unmistakable advantage over any potential enemy. Going to war with a smaller, “smarter” military led to devastating casualties at the beginning of World War II, in Korea and in Vietnam. Few would argue that a massive troop drawdown in the middle of a war is a smarter strategy or advances our national interest in any meaningful way.

A “flexible,” “agile” military resembles the force we had in 1991, when we deployed half a million troops to the Persian Gulf and decimated the world’s fourth-largest army with minimal casualties, all while we maintained our guard against a dying, but potent, Soviet Union. It is difficult to conceive how hollowing that force would have promoted balance, enhanced flexibility or qualified as a “smarter” strategy.

The British have a unique security strategy and equally unique fiscal challenges. They are meeting those challenges their own way. Separately, one of the great responsibilities of the American presidency is to maintain a stable global order. Our prosperity hinges on open sea lanes, an accessible Internet and open use of satellites and space. The president’s new defense strategy could end up damaging the sentry that keeps those realms secure.