One of the puzzlements I've had for some time is why there are so few experts on the politics of defense, especially in the role of Congress plays. One of the few people who genuinely has studied this subject (which is different from participating in it) is Pat Towell, who covered the politics of defense for decades until going upmarket and working for the Congressional Research Service.
I mention this because I've just been reading Towell's essay in a fairly new book, Congress and the Politics of National Security. I covered the military for decades, but I didn't realize it until reading the essay that the Armed Services Committees are anomalies, having unique and far more intrusive powers than do other committees. "The Constitution assigns Congress a degree of authority over the organization and equipage of the armed services that has no parallel in terms of the relationship of the legislative branch with other executive branch agencies," he writes. "The Senate Armed Services Committees draws particularly strong leverage from the fact that promotions for military officers-unlike those for civil servants-require Senate confirmation."
He also makes the broader point that congressional power is more negative than positive. "In general, it is far easier for Congress to block a presidential initiative than to force some course of action on a reluctant executive, simply because it is easier to mobilize a blocking coalition."
One quibble: He says that "talented members" still seek seats on the armed services panels. I wonder if that is still true. From what I've seen, since the end of the Cold War, congressional leaders have been stuffing freshman onto those committees.
I think there is a great dissertation to be done on successful congressional interventions in the Pentagon acquisition process. Imposing the cruise missile on a reluctant air force is one such example. Towell touches on this in an interesting passage about air mobility and strategic lift, but I would bet there is much more to be said.
Thomas E. Ricks covered the U.S. military for the Washington Post from 2000 through 2008.