President Donald Trump has signaled that he’s happy to fight a drawn-out war in Iran. The longer the conflict lasts, the more money the U.S. will have to spend replenishing its stock of missiles.

That’s good news for defense contractors, although there are major concerns about them running out of crucial technologies.

“With the recent attacks on Iran and escalation in the Middle East, we expect further increases in missile production will be required to restock the arsenal to maintain readiness,” Truist Securities analyst Michael Ciarmoli wrote in a research note.

Lockheed Martin, Northrop Grumman, L3Harris Technologies, Karman, Kratos Defense & Security Solutions, and Ducommon are the stocks that are most “exposed” to a surge in missile spending, Ciarmoli added.

The Trump administration plans to meet with defense executives on Friday and the Pentagon could seek an extra $50 billion in funding to support operations in the Middle East, Reuters reported on Wednesday, citing people familiar with the matter.

The White House didn’t immediately respond to a request for comment from Barron’s.

The big challenge for defense contractors is making missiles fast enough, given there are choke points in supply chains for components including castings, seekers, solid rocket motors, and other complex electronic components.

Production line speeds also vary, Ciarmoli said. Active or “hot” production lines that are already running typically take between eight and 12 weeks to make missiles, while cold lines building the technology from scratch can take 12 to 28 months.

The prospect of a drawn-out war in the Middle East has given defense stocks a significant lift this year. The iShares U.S. Aerospace & Defense exchange-traded fund is up 12% in 2026, compared with a 0.2% drop for the S&P 500.