KONGSBERG, Norway—A factory here west of Oslo produces a missile-defense system that can shoot down drones, helicopters and other airborne threats from almost 25 miles away.

Capable of launching 72 missiles into the sky at once, the National Advanced Surface-to-Air Missile System, or Nasams, is what protects the airspace over the White House. When first deployed in Ukraine in 2022, it recorded a 100% success rate shooting down cruise missiles and drones in its first few months.

With the West confronting a rising number of potential threats, including Russia and China, orders are piling up for the Nasams from Kongsberg Defence & Aerospace.

“I’ve never seen anywhere near so much demand,” said Eirik Lie, a 30-year Kongsberg veteran who is president of the company’s defense unit, on a November tour of the factory.

New customers, though, will have to wait: It takes two years to make one Nasams, and there is already a multiyear backlog.

The Ukraine war has highlighted the West’s deficiencies in quickly producing more weapons at a time of need. The Gaza conflict may tighten supplies for certain armaments.