Saturday’s strikes marked the biggest intervention by Western countries against Syrian President Bashar al-Assad and his ally Russia, which is facing further economic sanctions over its role in the conflict.
“There is a feeling (in the market) that there will be no follow-up action,” Rabobank fixed-income analyst Lyn Graham-Taylor said.
The Dow Jones Industrial Average rose 190.35 points, or 0.78pc, the S&P 500 gained 0.64pc and the Nasdaq Composite added 0.41pc.
“The action was well-received … and that’s giving a chance for investors to focus on macro news and earnings,” said Peter Cardillo, chief market economist at Spartan Capital Securities in New York.
The dollar index fell 0.3pc, with the euro up 0.28pc to $1.2364.
European shares eased, however, adding to a mixed picture from Asian stock markets and suggesting that a degree of caution prevails.
The pan-European FTSEurofirst 300 index lost 0.41pc. In Dublin the Iseq was up more than 1pc at 6,709.06. The gainers included takeover target Smurfit Kappa, up 3.25pc at €34.48 a share, and Kerry, up 3.29pc at €82.
Elsewhere, European and US government bond yields, which move inversely to prices, rose across the board.
Oil prices recouped some losses after falling sharply. Brent crude was last at $71.78, down 1.1pc on the day, with a rise in US drilling for new production also dragging on prices. US crude fell 1.34pc to $66.49 per barrel.