Oil prices jumped on Monday to their highest since January as the United States' weekend move to join Israel in attacking Iran's nuclear facilities stoked supply concerns. Brent crude futures were up 72 cents or 0.

Contracts for the S&P 500 declined around 0.3%. Global crude benchmark Brent jumped about 2.6% after surging as much as 5.7%. The dollar climbed against the euro and most major peers. Equity indexes in Japan and Australia fell less than 1% while Treasuries were little changed.

Global markets appeared to take the U.S. strike against nuclear targets in Iran in stride as investors watched to see how Iran will react. The price of oil initially jumped more than 2% but fell back slightly on Monday.