Hungry for defense deals, France has cozied up to the Gulf monarchies, winning several billion-euro contracts in the process, but its strategy of backing one side in the region’s Sunni-Shia power struggle is risky, say experts.

These are boom times for France’s defense industry, with the country signing €15 billion ($16.7 billion) worth of weapons deals this year — almost double its €8.1-billion tally for the whole of 2014.

Mounting chaos in the Middle East has prompted the oil-rich Gulf monarchies to arm themselves to the teeth, and they are increasingly reluctant to work with the United States, given its recent efforts to build bridges with their great rival, Iran. […]