The latest upheaval in President Donald Trump's administration is moving the U.S. closer to sparking a global trade war that could send the dollar plunging, in the eyes of at least one investor.

The risk that the U.S. pivots toward more protectionist policies is increasing with the departure of moderate voices, including Secretary of State Rex Tillerson and White House economic adviser Gary Cohn, said Paresh Upadhyaya, a portfolio manager at Amundi Pioneer Asset Management, which oversees about $83 billion.

He estimates the chances of a U.S.-led trade war are as high as 30 percent, and he sees that outcome pushing the dollar about 12 percent weaker, to $1.40 per euro, within two years. If the U.S. inflames relations with its trading partners, particularly China, and other nations retaliate against American protectionism, investors will likely sell the greenback and seek shelter in the yen, Swiss franc, and euro, he said. Stocks also stand to suffer, he said.