Donald Trump's move to strike Syria has won praise from many world leaders - with the notable exceptions of Russia and Iran.
While some of the reaction is in line with expectations, in other cases it runs contrary to traditional allegiances and the political divide.
In the US, some far-right supporters have slammed the reversal of policy from a man who had vowed not to get entangled in the Middle East.
But in Europe, most political leaders welcomed the move after the horror of the chemical attack widely blamed on Damascus.
Here is a look at supporters and critics.
The UK Government says it was informed in advance about the strikes and firmly supports the action.
Downing Street says it was "an appropriate response to the barbaric chemical weapons attack launched by the Syrian regime, and is intended to deter further attacks".
Liberal Democrat leader Tim Farron says it "was a proportionate response to the barbarous attack".
He wants Downing Street to call a NATO meeting "to see what else can be done ... more surgical strikes or no-fly zones".
"Evil happens when good people do nothing, we cannot sit by while a dictator gasses his own people. We cannot stand by, we must act."
Tom Watson, Labour's deputy leader, also backs the strikes - unlike his boss.
Hillary Clinton, the former Democratic candidate, has not commented, but just hours before the attack she was interviewed at a conference in New York and said: "I really believe that we should have and still should take out his air fields and prevent him (Bashar al Assad) from being able to use them to bomb innocent people and drop sarin gas on them."
EU Council President Donald Tusk says the US action shows "needed resolve against barbaric chemical attacks" and that the "EU will work with the US to end brutality in Syria".
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Turkey says it is a "very positive" development and calls for a continued tough stance that would render President Assad "no longer able to harm his people".
The strike is an "appropriate response" to the "unthinkable brutality" of the chemical attack, says Israel. Defence Minister Avigdor Lieberman says Mr Trump has sent a message that "war crimes" will not be tolerated.
Saudi Arabia welcomed the President's "courageous decision".
Premier Shinzo Abe says Japan's government understands and supports America's strategy and that the strikes are "a means to prevent further deterioration of the situation".
Bana Alabed, the seven-year-old Syrian girl whose tweets from Aleppo captured the horror of the war, welcomes the action "against the killers of my people". Bana now is a refugee in Turkey.
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Russia is President Assad's staunchest ally and Vladimir Putin called the strikes an "aggression against a sovereign state in violation of international law".
He said it would damage US-Russia ties and harm efforts to form an international coalition against terrorism.
Russian foreign minister Sergei Lavrov said a "far-fetched pretext" was used to justify the attack.
Iran, also an Assad ally, says it "strongly condemns any such unilateral action"as it will "strengthen terrorists" in Syria and complicate the situation in the region.
Labour leader Jeremy Corbyn says the attack "risks escalating the war in Syria still further".
While he calls the chemical attack "a war crime which requires urgent independent UN investigation", he says "unilateral military action without legal authorisation or independent verification risks intensifying a multi-sided conflict".
Mr Corbyn wants Downing Street to "urge restraint" from the US.
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The Scottish National Party says strikes are "no substitute for a policy towards ending the conflict".
Foreign Affairs spokesperson Alex Salmond believes the move introduces "further and dangerous unpredictability" into the conflict.
Some of Mr Trump's conservative supporters also denounced the missile strikes, including political commentator Ann Coulter, who tweets that "those who wanted us meddling in the Middle East voted for other candidates".
In Europe, some of the populist movements that saw Mr Trump's election as a victory against established politicians are condemning the action.
French far-right presidential candidate Marine Le Pen, who has expressed support for President Assad, says she was "surprised" at the attack.
She said Mr Trump had indicated he would not make the US "the world's policeman - and that's exactly what he did yesterday".
In Italy, the Five-Star Movement of comedian Beppe Grillo condemned the attack and demanded that Italy not get drawn in.
The anti-immigrant Northern League, whose leader is a fan of the US President, calls the strikes a "gift to ISIS".
France and Germany say in a joint statement that President Assad brought the strikes upon himself by using chemical weapons.
German Chancellor Angela Merkel and French President Francois Hollande say their countries will continue to work with UN partners in "efforts to hold President Assad responsible for his criminal acts" and call upon the international community to "join forces for a political transition in Syria".
Nigel Farage, a long-time supporter of the US President, expresses worry at the move. The former UKIP leader says: "I think a lot of Trump voters will be waking up this morning and scratching their heads and saying, 'Where will it all end?'
"As a firm Trump supporter, I say, yes, the pictures were horrible, but I'm surprised. Whatever Assad's sins, he is secular."
NATO chief Jens Stoltenberg, after initially declining to comment, says "the Syrian regime bears the full responsibility for this development. Any use of chemical weapons is unacceptable, cannot go unanswered, and those responsible must be held accountable."