U.S. allies are praising President Trump’s order on the U.S. missile attack against the Shayrat air base in Syria, which is believed to be the origin of Tuesday’s chemical weapons attack that killed more than 80 people in the Idlib province. Russia and Syria denounced the move Friday.

According to former CIA deputy director and CBS News senior national security contributor Michael Morell, Mr. Trump is sending a “very strong” message to Syrian President Bashar al-Assad and other foreign leaders watching: “You can’t use these weapons.”

“This will deter [al-Assad]. But we did not go after regime command and control, so that will also send him a message that we are not going to try to force him out militarily. So he will read both of those messages,” Morell said Friday on “CBS This Morning.”

Two U.S. Navy warships in the Mediterranean fired 59 Tomahawk cruise missiles in the strike, early-morning local time. Syrian officials say at least seven people died in the attack.

Fran Townsend, a former homeland security adviser to President George W. Bush and CBS News senior national security analyst, said sources within the Trump administration said “the driving principle is proportionality.”

“One, you didn’t want unnecessary civilian casualties when what you were doing was retaliating for the horrific civilian casualties. Two, you wanted to be careful not to be hitting other sites,” Townsend said. “There are six major airfields. We only hit the one from which where they launched this awful chemical attack. Because what you didn’t want to do is hit potential stockpiles and caused the plume where you caused the release of sarin or chlorine gas.”

Morell said one of the biggest successes of the attack was that the president acted decisively.

“He didn’t take weeks to try to bring other people on board. That’s a message that is going to be heard not only in Syria and in the region [but] around the world. I think that’s very important. And so I would encourage not waiting for others to join. I would encourage the president to continue to act decisively,” Morell said.

“By the way, if I was North Korea, the timing of this while President Xi is [in the U.S.] gives impetus to that conversation with the Chinese: ‘Look, we’re willing to act alone. That may not be our preference, but we need you to act with us,’” Townsend said.

Morell said Mr. Trump gets high marks for sending a message about chemical weapons, but he could get higher marks if he uses this moment to try to bring the world together and pressure Assad to “come to the negotiating table and end the civil war in Syria once and for all.”

“He has an opportunity to do that, and I hope he does it, and it has to start in Moscow next week,” Morell said, referring to Secretary of State Rex Tillerson’s upcoming meeting with Russian Foreign Minister Sergey Lavrov.

Morell said Tillerson’s Russia trip will be key.

“The Russians bear significant responsibility for what President Assad has done in Syria to his own people. They bear responsibility for the chemical attack last week, and it’s going to be very important for Secretary Tillerson to make that clear to Putin and to make it clear that his support for Assad has to stop,” Morell said.