Military crises around the world are boosting foreign demand for U.S. weapons, especially air and missile defense systems, spy equipment and armored vehicles, according to U.S. government and industry officials.

Weapons makers like Lockheed Martin, Northrop Grumman, Boeing and Raytheon anticipate new markets for their goods. And that could offset lower U.S. military spending.

Russian aggression in Ukraine is reviving long-dormant European demand, while the emerging militant Islamist threat in Iraq and Syria has underpinned already strong Middle Eastern demand. […]