Cruise missiles rained down on Syria from fighter jets, Predator and Reaper drones and from the sea on Tuesday of this week.
The US attack targeted the Sunni Islamist group Islamic State, formerly known as Isis.
The bombing threatens a new phase of imperialist war in the region, which US president Barack Obama has admitted could last for years.
David Cameron is keen to join the alliance bombarding the region.
The Syrian city of Raqaa took the brunt of the first bombs. Civilians have been living in fear since Obama announced he was preparing to bomb targets in Syria and Iraq.
Abu Ahmad fled the city with his family saying, “We will not stay in our homes waiting for death to find us.”
Another Raqaa resident, Ahmad al-Salem, said local people feel “the US acts without taking the Syrian people into consideration”.
France joined bombing raids on Iraq last week. The US claims its assault on Syria was joined or supported by Bahrain, Jordan, Saudi Arabia, Qatar, and the United Arab Emirates.
The US has launched over 190 air strikes on Iraq in the past fortnight. Warmonger Tony Blair has declared that ground troops must follow.
Many Tory MPs who opposed air strikes last year are lining up to support a new call to join the US assault on Iraq.
Cameron was defeated in his bid to bomb Syria last year and will want to ensure victory before another vote. That means winning Labour support.
Labour leader Ed Miliband has said he will back attacks if they have “a basis in international law”. This leaves a door open for Labour to support bombing Iraq when the West can claim its government has called for their support.
But there is no such cover if Labour supports bombing Syria.
The US had long said it did not want to get embroiled in a new war in the Middle East. US rulers wanted to draw a line under defeats in Afghanistan and Iraq.
But Islamic State gained territory so fast that it posed a real threat to US interests in the region.
Polls in Britain point to a shift in public opinion to supporting intervention. This follows the murder of Westerners and weeks of propaganda about the brutality of Islamic State.
But this can quickly change when the reality of a new imperialist war is exposed.
The West claimed that wars in Afghanistan and Iraq would stop the growth of groups such as Al Qaida and the Taliban. Instead their wars have produced Islamic State.
The latest war is being waged in the interests of Western leaders. Activists everywhere should mobilise against it.
Kurds flee Islamic State
Some 100,000 Kurds have fled to Turkey to escape Islamic State. Kurdish people have been displaced across the Middle East. The Turkish government launched a crackdown on the Kurds in the 1980s and 1990s. It destroyed around 3,000 villages and made three million people refugees.
Israel shoots Syrian plane
The Israeli government shot down a Syrian fighter jet on Tuesday. It shows how instability in the region could intensify. Israel has been keen to see Syrian president Bashar al-Assad remain in power as he has kept Syria’s borders with Israel secure.
Cameron seeks help from Iran
David Cameron met Iranian president Hassan Rouhani at the United Nations this week. It is the first time British and Iranian leaders have met since the 1979 Iranian revolution. The West sees Iran as a potential ally against Islamic State, although Iran backs the Syrian regime.
Protests called across the US
Anti-war activists have called demonstrations in cities in the US against air strikes in Syria. The anti-war coalition Answer stated, “This war, like the earlier ones, is being sold on the basis of misinformation and fear.”