Last week President Trump again called to revitalize the United States military, most notably with a 10 percent increase in the defense budget. Such proposals make for a snappy sound bite and enable the president to bask in the reflected glow of the armed forces, which happen to be more popular than he is. Yet in the absence of a coherent national strategy, arbitrary increases in the defense budget will do little to make America safer, and could make the world more dangerous.

There is no doubt that the United States faces serious security threats. The Defense Department is dealing with genuine readiness and modernization challenges, and reasonable people can disagree about whether targeted budget increases are a necessary remedy. Some experts see rising threats from North Korea and Russia and have called for augmenting the United States’ ground warfare capabilities after long campaigns in Afghanistan and Iraq. Others call for increasing funding for the Navy, which is slated to shoulder the cost of a new ballistic missile submarine — the backbone of the nation’s future nuclear force — even though this effort may squeeze out the service’s traditional shipbuilding.

Ideally, a coherent defense budget process would reflect these types of debates, prioritizing some threats over others and determining how best to combat them. In the real world, the defense budget is complex, politicized and hard to wrangle even when incoming administrations attempt to link their budgets to a vision. But they usually try.

For example, President John F. Kennedy’s defense secretary, Robert McNamara, proposed reducing funding for the Air Force because Kennedy had promised to move away from President Dwight D. Eisenhower’s emphasis on the service’s nuclear capabilities. Similarly, President George W. Bush’s first defense secretary, Donald Rumsfeld, focused his early efforts to reshape the budget on defense “transformation” to reduce each service’s legacy force structure while investing in information, stealth and precision technology. Neither president got exactly what he wanted, but each made a vigorous effort to link proposed changes to strategic priorities.