David Ignatius [“In a crisis, who should take charge?,” op-ed, March 3] leaves out a key reason — perhaps the key reason — for what he correctly identifies as the “power gap” that has plagued U.S. foreign and national security policy at least since the end of the Cold War. In a word: “money.”

Given that U.S. military functions (in the Pentagon and other agencies) dwarf non-military functions (in various agencies), is it any wonder that the State Department, USAID and other agencies that promote U.S. interests abroad are crowded out, with each fighting to protect its tiny part of the overall national security pie? And it is getting worse. Last year, the Joint Chiefs of Staff, which “owns” the National Defense University, heavily slashed NDU’s (already small) budget for research, which is necessary to design policies to do “more with less” and to integrate different tools of national security policy — at a time when spending on “what should we do and how best should we do it?” should go up, not down.

Once, in helping to design the Pentagon’s 2002 Quadrennial Defense Review, I listened to complaints by some senior military officers that the State Department was not “doing its job.” My rejoinder: “Why don’t you just buy it — out of petty cash?”

Robert Hunter, Washington

The writer, a former U.S. ambassador to NATO, was director of the Center for Transatlantic Security Studies at the National Defense University from 2011 to 2012.