A swooning Chinese economy. The rising specter of global jihad. Russia lurching toward a new Cold War with the West.

These are among the top threats facing the global economy, and now a leading risk analysis firm has added another wild card to its list: Donald J. Trump.

The Economist Intelligence Unit, based in London, has been carefully monitoring Mr. Trump’s march toward the Republican presidential nomination, and on Wednesday it warned in a report that a President Trump could be a drag on global growth.

“In the event of a Trump victory, his hostile attitude to free trade, and alienation of Mexico and China in particular, could escalate rapidly into a trade war,” according to the report. “His militaristic tendencies towards the Middle East (and ban on all Muslim travel to the US) would be a potent recruitment tool for jihadi groups, increasing their threat both within the region and beyond.”