International

Hundreds of Syrian fighters are en route to join Russian forces in Ukraine, effectively returning the favor to Moscow for helping President Bashar al-Assad crush rebels in an 11-year civil war, according to two people monitoring the flow of mercenaries.

A first contingent of soldiers has already arrived in Russia for military training before heading to Ukraine, according to a Western diplomat and a Damascus-based ally of the Syrian government. It includes at least 300 soldiers from a Syrian army division that has worked closely with Russian officers who went to Syria to support Mr. al-Assad during the war.

And many more could be on the way: Recruiters across Syria have been drawing up lists of thousands of interested candidates to be vetted by the Syrian security services and then passed to the Russians.

Syria has grown in recent years into an exporter of mercenaries, a grim aftereffect of years of war that gave many men combat experience but so damaged the country’s economy that people now struggle to find work. So they have deployed as guns-for-hire to wars in Libya, Azerbaijan, the Central African Republic — and now Ukraine.