Are we on the road to World War Three?
Donald Trump, the US president, has thanked Britain and France for the "power of their fine military strike" after the allies responded to a chemical attack in Syria.
The Pentagon announced that they believe they have dealt a severe blow to the Syrian regime and destroyed their capability to carry out another chemical attack.
The allied coalition took out research facilities involved with the research and development of chemical weapons, a Pentagon official said.
The US said that 105 missiles had been fired in the strike at the three targets.
Announcing the start of the strikes on Friday evening, Mr Trump had some strong words for Russia, which backs the Syrian regime in the war, directly singling out President Vladimir Putin for supporting the "barbarism and brutality".
His comments will ratchet up tensions between the two former Cold War foes.
"What happens next depends on what the Assad regime decides to do," Dana White, the Pentagon's chief spokesperson, said at a press conference yesterday.
"The Russian disinformation campaign has already begun, therefore we will keep you abreast of the facts moving forward."
The attack came days after Mr Trump warned Syrian President Bashar al-Assad and President Putin to "get ready" for missiles, the strongest rhetoric he has used since entering office.
The true impact of the US and its Western allies' missile strikes has yet to be fully established, but they have at least played a symbolic role in showing a commitment to retaliation against chemical weapons attacks.
Mr Assad, who has for years been acting with impunity as the international community sat on its hands, will be carefully watching to see what the allied coalition does next.
A US Tomahawk missiles strike on a government air base after last year's deadly chemical attack was a sharp tap on the wrist that succeeded in destroying a few jets, but no meaningful response followed.
Friday evening's strikes were an announcement of the open-ended bombing of President Assad's forces unless he stops using his chemical weapons.
Behind the scenes, Washington, Paris and London had been discussing a possible trilateral response to any such chemical attack.
The combat mission represents British Prime Minister Theresa May's first significant military decision in the job. On Friday night she stressed: "This is not about intervening in a civil war. It is not about regime change. It is about a limited and targeted strike that does not further escalate tensions in the region and that does everything possible to prevent civilian casualties."
However the joint strike between the UK, France and America suggests Britain's next steps will be decided upon in tandem with the allies.
The coalition will be looking not to get dragged further into the intractable conflict, particularly Mr Trump who had campaigned on getting America out of Middle East conflicts.
But what about Israel?
It looks as though the strike on T4, or Tyras, base in Homs, central Syria, in the early hours of Monday morning was from Israel.
Israel is not part of the US-led coalition and its decision to unilaterally strike will be seen as the Jewish state acting in its own national interest.
It likely had its own intelligence about Syrian government and Iranian assets on the ground, which it was keen to destroy before it had the chance to move anything like it did after before last year's Tomahawk strike.
Iran is a key backer of Mr Assad.
So will there be a World War Three?
It is unlikely. We have been here before and both the US and Russia have looked to avoid a direct confrontation at all costs.
Having said that, the political landscape has changed considerably in the last year. US and Russia relations are as bad as they have ever been under Mr Trump.
The US has expanded sanctions against Moscow and expelled a number of its diplomats over the poisoning of former Russian spy Sergei Skripal and his daughter Yulia in Salisbury.
"We're not heading to a nuclear war with the Russians, but this is a dangerous period," said Ian Bremmer, president of geopolitical-risk firm Eurasia Group.
"If the Americans engage in direct strikes against Assad - given their direct support by the Russians and the Iranians - it is a dangerous thing to do, but I do think that it's an appropriate thing to do in this environment."
The Russians have too much invested to back down and Mr Trump has already signalled he is willing to act against atrocities such as chemical attacks.
However, Russia's decision not to engage its sophisticated missile defence system to shoot down the allies' strikes suggests they are unwilling to be drawn into a direct conflict with the US.