One of the salient lessons stemming from the ongoing Russo-Ukrainian War for NATO and the U.S. in any potential conflict with a near-peer adversary is to win quickly or be prepared to support a long fight, the top U.S. general in Europe said last Friday.

Winning early requires a combination capabilities, capacity, and readiness, Army Gen. Christpher Cavoli said at an event hosted by the Atlantic Council.

“So, I think the first lesson is you either win upfront, fast and big, or you’re in a long fight,” the commander of U.S. European Command and Supreme Allied Commander Europe, said. “So, step one, is to develop high-end capabilities and capacity at a high level of readiness, so that you can win the first fight out of the out of the starting blocks. Because what we see in Ukraine is if you don’t, and you’re facing a large adversary like Russia, you’re going to end up in a long, protracted fight.”

The long fight requires a lot of personnel, reserves, industrial capacity that is already producing or ready to go, and the ability to mobilize equipment and munitions “in sufficient stockpiles,” Cavoli said.

NATO members have work to do with manpower, Cavoli said, describing it as “one of the biggest strategic challenges that we face as an alliance.” Human resources are something members “have to come to grips with,” requiring increases and accessibility “in the same way that industrial resources and production and war stocks are,” he said.

And while there are tactical lessons, a second key takeaway from the war is use of plentiful, inexpensive, and effective drones as a component of air warfare, he said.

“We do see that drone warfare is sort of democratizing the third dimension,” Cavoli said. “Just about everybody on the battlefield can get something into the air now and affect you from the air.”

Drone warfare continues to play out for both sides in the conflict and the lessons from observing this are “easy to overstate,” Cavoli said. Still, the “widespread” and proliferated” use of small drones “throughout the ranks and formations, I think that’s something new we’ll have to deal with,” he said.

Cavoli was asked about the “interplay” between the air forces of the different NATO members and the alliance to conduct close air support missions. For close air support, Cavoli acknowledged there are challenges but said the combination of fifth and fourth-generation fighters used by NATO members allows for both “exquisite” fighter and close support missions.

“Of course, focusing on the exquisite end of aerial combat, means you’re probably not able to focus as much on close air support and things like that,” he said. “And that’s something we’re wrestling with inside the alliance. The good news is that the alliance does retain a huge number of fourth generation aircraft. So, we still have the capabilities to do it. And we’re looking through the ways that you maintain both capabilities going far into the future.”

Cavoli also stressed the civil-military relations in the war, highlighting that this is an advantage for NATO members.

“When civilian leadership is good and strong, it can galvanize the nation, and when it interacts in a positive and constructive fashion with military leadership it produces results on the battlefield,” he said.