The Stoxx Europe 600 retreated for a third day and U.S. equity futures slumped, tracking losses across Asia, where Chinese shares plunged after reopening following a holiday. President Donald Trump warned America will slap tariffs on more Chinese goods, and the Asian nation threatened retaliation. The stock move in Europe was tempered by a weaker euro, however, which dropped after the latest’s dovish message from ECB President Mario Draghi. The British pound was also under pressure as U.K. Prime Minister Theresa May prepares for another knife-edge Brexit vote on Wednesday.

Meanwhile, the lurch toward protectionism rattled commodities and commodity-linked currencies, which retreated across the board. The Cboe Volatility Index rose the most in three weeks, while government bonds in Europe rallied alongside U.S. notes.

Tough trade talk is nothing new for investors in 2018, but a sense that stress is ratcheting up between the U.S. and China is taking a toll on markets. The protectionist moves come at a time when many are already voicing concern that global growth could lose momentum as it also contends with America’s faster tightening of monetary policy and the end of European stimulus.

“What you saw at the start of the year was global synchronized growth,” Emad Mostaque, co-chief investment officer at Capricorn Fund Managers, said in an interview on Bloomberg Television. “It was a cooperative game. Now, we’re moving to a more competitive, negative-sum game.”

Emerging markets were in turmoil as the implications of a possible trade war filter through to investors. Developing-nation stocks headed for the biggest drop since March, and currencies slid as the South African rand and Turkish lira led declines.

Elsewhere, oil fell with other commodities, paring Monday’s jump as traders weigh OPEC’s discussions on a compromise over increasing output ahead of a meeting in Vienna this week.

Here are the main market moves:

Stocks

The Stoxx Europe 600 Index declined 0.7% as of 7:08 a.m. New York time, to the lowest in almost three weeks. Futures on the S&P 500 Index sank 1.1% to the lowest in more than two weeks on the biggest tumble in eight weeks. The U.K.’s FTSE 100 Index dipped 0.5% to the lowest in six weeks. Germany’s DAX Index decreased 1.4% to the lowest in almost three weeks. The MSCI Emerging Market Index sank 2%, hitting the lowest in more than eight months with its fifth straight decline and the largest tumble in more than 12 weeks. The MSCI Asia Pacific Index sank 1.6%, reaching the lowest in more than six months on its fifth consecutive decline and the biggest tumble in almost 12 weeks.

Currencies

The Bloomberg Dollar Spot Index increased 0.4% to the highest in more than 11 months. The euro decreased 0.7% to $1.1547, the weakest in three weeks. The British pound declined 0.5% to $1.3173, the weakest in seven months. The Japanese yen climbed 0.6% to 109.85 per dollar, the strongest in more than a week on the biggest increase in almost four weeks. The Turkish lira sank 1.3% to 4.7663 per dollar, the weakest on record.

Bonds

The yield on 10-year Treasuries fell four basis points to 2.87%, the lowest in almost three weeks on the biggest drop in more than a week. Germany’s 10-year yield declined four basis points to 0.36%, hitting the lowest in almost three weeks with its sixth straight decline. Britain’s 10-year yield dipped five basis points to 1.324%, reaching the lowest in almost three weeks on its sixth straight decline and the biggest decrease in three weeks. Italy’s 10-year yield dipped one basis point to 2.546%, hitting the lowest in more than two weeks with its fifth straight decline.

Commodities

West Texas Intermediate crude fell 1.5% to $64.84 a barrel, the lowest in almost two weeks. Gold increased less than 0.05% to $1,278.60 an ounce. Brent crude declined 0.7% to $74.81 a barrel.