Washington usually cloaks its most critical defense programs in secrecy.

But in the case of using cyberstrikes, electronic warfare and other exotic forms of sabotage to redefine antimissile defense for the United States, many high-ranking officials and officers have been talking openly, often to persuade Congress to fund the secretive efforts.

The public conversation about the new antimissile approach, known as “left of launch,” has been careful. Typically, military leaders and contractors have spoken vaguely about technologies and targets. But at moments they have also declared that it is all about North Korea and Iran, at least for now.

The idea is to strike an enemy missile before liftoff or during the first seconds of flight. The old approach waited until much later — after swarms of warheads had been released, had traveled thousands of miles and were racing toward targets at speeds in excess of four miles a second.

Officials have praised left-of-launch strikes as a novel way of knocking out enemy missiles at a tiny fraction of the usual cost. In presentations and congressional testimony, senior officials have described the method as a potentially revolutionary way to strengthen the defenses of the United States.