The Pentagon in December 2011. (AFP/Getty Images)

In rejecting one statistic regarding the size of the U.S. defense budget, Robert J. Samuelson missed the point and undermined his own argument in his Jan. 28 op-ed, “The truth about defense spending.”

The United States now spends more on the military, in inflation-adjusted dollars, than it did at the height of the Korean War, the Vietnam War or the Cold War. More than half of all discretionary spending goes to the Pentagon. Our warfighting capabilities far exceed those of all potential rivals, yet most of the threats we face — extreme inequality and injustice, climate change, nuclear proliferation, violent extremism and cyberattack — have no military solutions.

Mr. Samuelson was correct that “the United States has assumed strategic responsibility for ensuring stability in Europe, Asia and the Middle East. Neither China nor Russia has yet embraced similarly sweeping goals.” And that’s exactly the point: We spend too much because too often, in too many places, we continue to “assume” missions that are counterproductive, overly militarized and no longer relevant.

Diana Ohlbaum, Washington

The writer is senior strategist and legislative director for foreign policy at the Friends Committee on National Legislation, and chairs the board of the Center for International Policy.

As a former Pentagon cost analyst and Army veteran, I read Robert J. Samuelson’s Jan. 28 op-ed, “The truth about defense spending,” with great interest. He offered a useful comparison of nations’ defense budgets using purchasing-power parity and laid out a set of descriptors for U.S., Russian and Chinese militaries. 

True, using purchasing-power parity offers an added perspective on comparative spending, but purchasing-power parity does not speak to comparative quality. In terms of personnel, tactical ships, combat aircraft and tanks, the gaps among the U.S., Russian and Chinese militaries appear to be narrowing. But such a list does not speak to the quality of personnel and training, equipment readiness and the effectiveness of the combat formations — brigade combat teams, fighter wings and strike groups — to which weapon systems are assigned. No doubt in my mind: I’d put our top-notch force up against any adversary. Size matters. But capabilities matter more. 

This year, the Congressional Budget Office projects that our deficit will be $900 billion, and our national debt now stands around $22 trillion. Going forward, every dollar spent must produce results; for national defense, we need to strive for the biggest “bang for the buck.” The administration’s anticipated request for defense in 2020 of upward of $750 billion — the highest amount ever requested for defense — should give us more than enough of the bang that we need.

Walt Cooper, Falls Church