The US cruise missile strikes on a Syrian airbase in Homs bore the hallmarks of a one-off message.
Washington tipped off Moscow to prevent Russian forces being hit, and the Russians almost certainly warned Damascus about what was coming.
Syrian officials reported nine deaths in the strikes, including of civilians, while the US and Russia offered conflicting accounts of the damage caused. Russia said six planes being repaired in hangars were destroyed, but other jets at the base were untouched. Photos circulated during the day showed hangars burnt but still standing and a runway that appeared to be intact. Russia’s defence ministry said only 23 of the 59 missiles fired reached the base, while a US military official said 58 missiles struck their targets.
The US said the strikes were a “proportional response” to discourage the Syrian government from turning to chemical weapons again – and that is what they appear to be.
The attack may succeed in deterring the government of Bashar Al Assad from further use of chemical weapons as it now knows that the US will respond. But if the US intends to strike only when chemical weapons are used, this will not stop the many other atrocities frequently committed by Mr Al Assad’s forces or hasten an end to his presidency.
Civilians killed in chemical attacks are a small percentage of the Al Assad regime’s victims. For years the Syrian air force has hit residential areas with little regard for collateral damage. Hospitals have been targeted systematically, denying injured civilians life-saving treatment. Sieges have tried to starve out entire towns and cities. Civilians have disappeared and others have simply been executed. Damascus proved a long time ago that it does not need chemical weapons to make people suffer in the worst ways imaginable.
It appeared to be business as usual for the Syrian government after the US strikes. During the day Syrian jets were still in the skies and the town of Khan Sheikhoun – the site of the chemical weapons attack on Tuesday that prompted US intervention – was bombed once again.
But while the US has indicated that the strike was a warning shot, it is worth considering the possibility of continued military action.
Despite stressing the limited scope of Friday’s action, the Trump administration is now talking about the need to remove Mr Al Assad from power and that can be done only by further intervention or by strengthening his opponents.
For the moment, Mr Trump is loved by Syria's rebels and their friends across the Middle East. For years they have been asking for help, for a foreign power to go after the Syrian government directly to even up the fight. And for years their pleas have been ignored. Mr Trump, a man some Syrians believed would turn a blind eye to their plight, finally answered their call.
The leaders of the Syrian opposition welcomed the strikes and are asking for more. Turkey on Friday called for the establishments of “safe zones” and no-fly zones in after the strikes. Other US allies are also likely to press Washington to keep up the pressure.
If the US does continue strikes, the effect could be significant. Taking out the Syrian government’s air power would help rebels on the ground who, since the beginning of the conflict, have complained that the regime’s jets and helicopters were the main obstacle to success.
US involvement could also serve as a unifying factor for Syria’s fractured rebels, providing hope and finally something to rally around.
Whether Mr Trump will actually take action that significantly helps Syrian rebels remains to be seen. The US president is a man who liked to put quotation marks around the word “rebels” in his tweets about Syria’s war and he has repeatedly suggested they cannot be trusted. But then again, as this week has shown, Mr Trump is a man who can change his mind abruptly.