The US Air Force's director of force design said America can't win through long-range strikes alone.He said the Air Force wants to emphasize more long-range strikes but cannot rely on them too heavily.US air power would need both tempo and mass to win a war, he said.The US Air Force relying on a "massive punch" from afar would be a war-losing mistake, said its general in charge of shaping the service's future capabilities."What we have found, if you go to an all-long-range force, it doesn't win," Maj. Gen. Joseph Kunkel said at a Hudson Institute event on Wednesday.He was answering a question about whether the Air Force will start to heavily or completely emphasize long-range strikes."I mean, it sounds wonderful, doesn't it?" Kunkel said, who also oversees the Air Force's war game simulations. "You sit in Topeka, Kansas. You press a red button. The war gets fought. Nobody gets hurt. It's all done at long-range."But Kunkel said the strategy doesn't work because the Air Force loses tempo when fighting that way."They're absolutely game-changing," he said of striking from long range. "They're going to help us out. They're going to be able to deliver a massive punch to the adversary.""But they're probably not going to do it at the tempo that's required to keep the adversary on its knees all the time," Kunkel continued.He said that to win wars, the Air Force still needs to be able to get close and strike frequently."You need something else. You need something inside. You need something inside that can generate tempo. Tempo and mass," the general said.To that end, Kunkel said the Air Force would transition to include more long-range attack methods but still rely on combined arms a mix of different capabilities.The Air Force has repeatedly signaled that it's trying to bolster its long-range strike capabilities, especially as the Pentagon worries about open conflict with China.In January, for example, then-Air Force Secretary Frank Kendall said the force might have too few options to attack from afar.The new B-21 Raider Bomber unveiled in 2022 is a central piece of the Air Force's long-range capabilities, and Kendall hinted that it needed more than its planned fleet of 100 aircraft."The Air Force is very heavily dependent on relatively short-range aircraft: fighters. And has a relatively small inventory of longer-range strike platforms: bombers," Kendall said. "I think that balance needs to shift."Still, Kunkel said explicitly on Wednesday that the Air Force wouldn't rely solely on long-range strikes."I will adamantly say we are not transitioning to this all long-range force because, alone, that just doesn't work. We will transition to elements of a long-range force," he said.The two-star general also said that the Air Force needs to start tailoring its capabilities to meet specific threatsand that simplymaking new fighter jets will not win wars for the US."When we do the analysis, what we find is just reinventing the Air Force doesn't win," Kunkel said.The Pentagon's press department did not respond to an additional request for comment for Kunkel sent by Business Insider outside regular business hours.