Discussion of the “fiscal cliff” since the presidential election has focused so far on the type and amount of tax increases that congressional Republicans might accept and the changes in entitlement programs that President Barack Obama and Democrats could agree to in exchange.

Sooner or later, however, the negotiations must turn to the crucial subject of defense spending. The automatic spending cuts due to kick in at the beginning of next year include $56.5 billion from the Pentagon, more than 10 percent of its base budget. If left unchanged, the sequester would cut defense by $454 billion over a decade.

Democrats who talk about “going over the cliff” as a way to gain leverage over Republicans on taxes may not have fully considered what this could mean for the military.

While bases would remain open, uniformed personnel would remain on duty and operations in Afghanistan would continue, the Defense Department could be forced to fire more than 100,000 civilian workers in the first weeks of the new year, according to a study by the Center for Strategic and Budgetary Assessments.

Training for non-deployed forces probably would be cut back substantially, leading to a dangerous drop in readiness. Spending on shipbuilding and other procurement would drop by 4.5 percent in 2013, causing significant layoffs by defense contractors.

Even if these disruptions can be avoided, new cuts in defense are likely to be part of any budget deal, though the Obama administration implemented two rounds of trims in the base Pentagon budget during its first term while winding down the wars in Iraq and Afghanistan.

The reductions already made are risky, since they assume the United States will no longer be required to fight prolonged land wars, and they will lead to a gradual shrinking of the Navy at a time when U.S. strategy is to increase its presence in the Asia-Pacific region.

To avoid further damage, new cuts must skirt areas that affect core U.S. forces, such as troops, equipment, training and the modernization of weapons systems. While there is potential for substantial reductions outside these areas, achieving them would require a sea change in Congress, which has shielded the fat of the Pentagon budget.

A starting point would be the legions of analysts and other staff posted to military headquarters and to the Pentagon itself; though 100,000 layoffs are not called for, thousands of duplicative jobs could be trimmed.

Next would come changes in costly and wasteful health-care programs, which consume nearly 30 percent of the budget. Even simple reforms, such as giving military personnel incentives to use generic drugs and making the government a secondary payer for health costs of retirees with private-sector jobs, could save billions.

Last but hardly least, unneeded defense infrastructure could be shut down if Congress would only allow it: bases, depots, National Guard facilities and more.

The pressure of the budget crisis should provide an impetus for a bipartisan effort to address such wasteful spending. At stake is something more than tax dollars: the ability of the United States to maintain its place in the world.

Editorial by The Washington Post