Current missile defenses rely on shooting down the incoming weapon – and usually when it is relatively close to the target.
Lieutenant General David Mann on Wednesday said the Pentagon is now more open to discussing the possibility of taking an offensive approach "left of launch," or before enemy missiles are fired.
"When you talk about left of launch and taking actions in a proactive manner, that comes fraught with a lot of policy issues," Mann said. "[But now] we're seeing a lot more openness to really discuss that especially at the department level, to really look across the whole spectrum of options."
"I see a lot more interest and willingness to discuss left of launch than I've ever seen before," Mann added. "When you hear the Joint Staff and others talking about holistic, non-kinetic, left of launch [options], you know you’re gaining some ground."
In May, then-outgoing Vice-Chairman of the Joint Chiefs, Admiral Sandy Winnefeld, urged caution when it comes to left-of-launch actions.
"While we would obviously prefer to take a threat missile out while it’s still on the ground, what we would call left of launch, we won't always have the luxury of doing so," Winnefeld said. "We don't want there to be any doubt about our commitment to having a solid right-of-launch capability."
Mann on Wednesday told Defense News that left of launch is meant to be one of multiple options that the United States needs for missile defense.
"At the end of the day, whoever's in charge of the campaign is the one that’s going to see what gets employed," he said.
The US missile interceptors are not enough to mitigate the threat posed by the growing number of countries that now have ballistic missile capabilities.
"Gone are the days where we could simply provide enough interceptors to address all the threat vehicles that are out there," Mann said. "We're faced with relatively inexpensive ballistic missiles and cruise missiles, and as good as our interceptors are, we’ll never have enough."
Last month, retired Air Force Lieutenant General Trey Obering, a former Missile Defense Agency director, said US missile defenses are not enough to counter the threat from Iran and North Korea, let alone "the increasingly sophisticated threats from China and Russia."