President Donald Trump on September 18 announced what he said would be substantial new sanctions against Iran in the first response to what U.S. officials say was likely Iranian involvement in an attack on Saudi oil facilities.
“I have just instructed the Secretary of the Treasury to substantially increase Sanctions on the country of Iran!” Mr. Trump tweeted.
The United States already enforces widespread sanctions that have crippled Iran's economy, including attempting to shut down its major oil export industry.