Updated April 15, 2018 08:13:16

Photo: A Syrian soldier films the damage of the Syrian Scientific Research Centre which was attacked by US, British and French military strikes. (AP: Hassan Ammar)

"Mission accomplished!" Donald Trump tweeted the morning after the night before.

"A perfectly executed strike," he said, in reference to the three-country mission that took out chemical weapons research, development and storage facilities in Syria.

The US and its allies, France and Britain, have drawn a new red line on chemical weapons, but the Pentagon admits that capacity in that area still remains.

The strikes also did not target the Bashar al-Assad regime's use of, or access to conventional weapons.

The US-led missile strikes on chemical weapons targets went further than the attacks of 12 months ago, but the impact is far less than the "World War III" many feared.

At a Pentagon briefing, director of the Joint Chiefs Lieutenant General Kenneth F McKenzie said the strikes were precise, overwhelming and effective, but that some of Syria's chemical weapons infrastructure remained.

"I think we've dealt them a severe blow," he said.

"[But] I would say there's still a residual element of the Syrian program that's out there.

"I'm not going to say that they're going to be unable to continue to conduct a chemical attack in the future. I suspect, however, they'll think long and hard about it."

At an emergency meeting of the UN Security Council, the United States ambassador Nikki Haley warned that further strikes would come if chemical attacks continued.

"I spoke to the President this morning and he said, 'If the Syrian regime uses this poisonous gas again, the United States is locked and loaded'," she told the meeting.

"When our President draws a red line our President enforces the red line."

The US appeared to have drawn that line this time last year, when it launched 59 Tomahawk missiles into Syria in response to a similar attack.

The recent attack at Douma was the 10th since that unilateral US missile strike in 2017, and while Mr Trump is vowing to act should such attacks continue, he has made clear he does not want to deepen US involvement in Syria.

Just a few days ago, he voiced his desire to pull US troops out altogether. Sources suggest he wants them out within six months.

On that basis, some of the reaction to the latest mission has been muted amid concern it will again be relegated to mere symbolism rather than bringing about any real change in Syria.

At the UN, Russia accused the US, UK and France of "hooliganism in international relations", again claiming the attack at Douma was staged as an excuse for an attack on the Assad regime.

The scientific facilities targeted in Syria are used only for peaceful means, the Russian ambassador claimed, calling for a vote for the allied group to immediately end its aggressive actions.

US Senator Ben Sasse, a member of the Senate Armed Services Committee, issued a statement after the Pentagon disclosed that Russia had increased its online troll activity by 2,000 per cent in the last 24 hours.

Photo: The air strikes were confined to Syrian military infrastructure to avoid Russian and Iranian casualties. (AP Photo: Hassan Ammar)

"Americans need to understand that the wars of the future will look more like this," he said.

"Russia is investing significant resources to create propaganda and disinformation.

"Kinetic, cyber, and information contests will overlap more and more in the coming years.

"The fog of war will not be limited to our situation rooms and battlefields; our enemies will work to create confusion and distrust among Americans here at home."

Several Democrats have questioned the administration's actions without congressional approval.

Topics: unrest-conflict-and-war, world-politics, government-and-politics, foreign-affairs, syrian-arab-republic, united-states, russian-federation

First posted April 15, 2018 06:05:50