Worse, local considerations and the quest for short-term political advantage give members of Congress perverse incentives to resist the least-damaging cuts, such as closing redundant military bases. Defense Secretary Chuck Hagel’s recent force-reduction proposals are the harbinger of even deeper and less popular cuts in the future. Forget about the two-war doctrine. The question a decade hence is whether we’ll be able to wage even one.

As for the president’s 2015 budget provisions for investment, the fine print tells the story. The document trumpets Mr. Obama’s commitment to research and development, but the numbers don’t back it up. Corrected for inflation, overall spending for R&D is flat, while funding for basic research actually declines by 2%.

That last figure is especially troubling because basic research doesn’t lend itself to being precisely targeted: By definition, we don’t know where the next big breakthrough in medicine, information, energy or other sectors will occur. We might get lucky, of course. But history suggests that if we want to increase the pace of path-breaking innovation, boosting the overall level of investment is essential. And history confirms what economic theory predicts. Without vigorous public participation, the private market will not produce an adequate amount of basic research—especially in a hypercompetitive global market.