The safe-haven yen climbed against the dollar and euro on Friday and the ruble tumbled, after the United States launched cruise missiles at an airbase in Syria, raising tensions with Russia.
In the biggest foreign policy decision of his presidency so far, Donald Trump ordered the move after a chemical weapons attack killed at least 70 people this week. It catapulted the United States into a confrontation with Russia, which has military advisers on the ground assisting the Syrian government.
The ruble skidded around 1 %, putting it on course for its biggest one-day falls in a month.
The yen, which investors tend to flock to when they perceive an increase in political or financial risk, strengthened to an 11-day high of 110.135 to the dollar in Asian trading, in the immediate aftermath of Trump's announcement.
By 1115 GMT, though, it was up just 0.1 % on the day at 110.68 yen per dollar. Stocks also recovered from earlier losses.
The dollar index, which gauges the greenback against a basket of six major rivals, inched up 0.2 % to 100.84, close to a three-week high.
"Asset markets have taken Washington's airstrike against Syria in their stride, at this stage viewing it as an isolated response to the horrific use of chemical weapons," said ING's head of currency strategy in London, Chris Turner.
"Only if the Trump administration started to look at far more comprehensive foreign policy action, requiring Congressional approval, might the dollar sell off more."
A weekly U.S. labor market report, due at 1230 GMT, is expected to show an increase of 180,000 jobs in March, according to economists polled by Reuters. That could reinforce expectation the Federal Reserve will deliver two more interest rate increases this calendar year.
But UBS Wealth Management's head of currency strategy, Constantin Bolz, said the labor market data was at the moment less important to the Fed's considerations on monetary policy than inflation data and global financial market pressures.
"The US labor market is fine – it doesn’t really matter if payrolls come in 10,000 or 15,000 higher or lower," he said.
The euro added to losses the previous day on the back of dovish comments from the European Central Bank chief, who said he saw no reason to deviate from the ECB's policy path, which includes sub-zero interest rates and bond-buying until at least the euro of the year.
The single currency hit a three-week low of $1.0626, and earlier hit a 4 1/2-month low against the yen.
The U.S. air strike came during a two-day summit between Trump and Chinese President Xi Jinping and will add a new dimension to their talks.
The meeting had a strong focus on trade and North Korea's military program. Trump had warned that he would be ready to act unilaterally to address North Korea's nuclear program if China does not step up to help in the matter.