BEIRUT—In a moment of need, reeling from a devastating attack on key oil facilities, Saudi Arabia is finding few friends these days in Washington or across the U.S.

The kingdom’s unpopular war in Yemen, its lackluster response after a Saudi hit team killed prominent critic Jamal Khashoggi and renewed attention to allegations of a Saudi government role in the 2001 terrorist attacks have damped support Riyadh may have hoped to get after alleged Iranian airstrikes.

“This was an attack on Saudi oil assets and should not provoke a broader war between the United States and Iran,” Sen. Chris Murphy (D., Conn.) told The Wall Street Journal. “We don’t have a mutual defense treaty with Saudi Arabia.”

Even President Trump, who has vetoed congressional efforts to reduce military support to Saudi Arabia’s war in Yemen, has made it clear that American support will go only so far, agreeing to send a small number of troops but stopping short of U.S. military action.

The Pentagon on Thursday further said it would send one new Patriot missile defense system, four small radar systems to help detect cruise missiles, and 200 more American military personnel.