A reversal of President Barack Obama’s outreach to Cuba, as threatened by President-elect Donald Trump this week, would leave a bigger opening off the U.S. coast for another great military power. It likely wouldn’t be Havana’s traditional ally Russia, however, but China.

While Moscow’s economic and military role in Cuba is now a shadow of its former self, Beijing has grown to become Cuba’s second-largest trading partner after Venezuela, which is now mired in a deep economic crisis.

Over the past few years, the U.S. role in Cuba’s economy has grown quickly. Cuban-Americans now send an estimated $3.4 billion in cash remittances to relatives in Cuba—more than the country’s total annual exports, and up from $1.92 billion in 2010. Cubans also get $3.5 billion worth of merchandise such as shoes, clothing, TV or computers from their relatives in the U.S. every year.

Thanks to the U.S. trade embargo, however, the U.S. remains a small player in two-way trade, accounting for only 1.54% of Cuba’s imports.

“If those links are severed because of a change in U.S. policy towards Cuba, you’d be choking Cuba’s population, increasing risks of a huge migration wave,” said Emilio Morales, head of the Miami-based Havana Consulting Group, a Cuba business consulting firm.