Since the Ottoman Empire traded swords for guns two centuries ago, Turkey’s military has relied on Western arms and know-how. Now, the country’s leadership is pushing to end that arrangement in a shift that is rattling its North Atlantic Treaty Organization allies.

Ankara has recently moved to diminish Turkey’s military dependence on the West, including last month inaugurating rocket testing and a radar technologies facilities. Both are part of Turkey’s effort to boost a fast-growing arms export industry that also is supplying its own forces with locally built tanks, warships, drones, missiles and—by the republic’s centenary in 2023—a jet fighter.

Ankara has also rejected bids by its NATO allies for a missile-defense system in favor of a Chinese-built one that one these partners say is incompatible with their technology and threatens intelligence cooperation. […]