At stake in Syria is the potential for confrontation, if not outright conflict, between the US and Russian Federation, former Cold War foes whose relations have deteriorated in recent years over Moscow's intervention in Ukraine, its interference in the 2016 USA presidential election and, most recently, its support for Syrian President Bashar Assad.
U.S. President Donald Trump said Thursday the National Security Council would meet and that decisions on Syria will be made "soon".
Instead, Mallinson argued crude futures had soared to multi-year highs on the back of two main price drivers - concern over the "wider ramifications" of heightened geopolitical tension in the Middle East and the looming prospect of the US withdrawing from the Iran nuclear deal.
His warning was in response to an alleged chemical attack near Damascus on Saturday.
Macron's office and the French military aren't commenting on pending plans.
After a meeting on Thursday, the Cabinet agreed to take action with allies against the Assad regime but no further information on timing has been announced.
It appears the British Parliament will not be consulted ahead of the United Kingdom action - which could potentially start within hours of Cabinet approval.
"Either of those actions are created to interfere with an investigation that may implicate the President", House Intelligence Committee ranking member Adam Schiff said on CNN's "The Situation Room".More news: Facebook's Mark Zuckerberg faces second day of questioning before US Congress
More news: Russian Federation says Syria chemical attack was 'fabricated'
More news: Child's body found in California river where family vanished
U.S. House of Representatives Speaker Paul Ryan said Thursday the U.S. has an obligation to lead an global response to the attack, and that Trump has the authority to use military force.
"I think it looks pretty clear that a chlorine weapon was used" on the civilians, said Charles Duelfer, former deputy head of the United Nations inspections team in Iraq, in an interview with NPR.
Meanwhile, the British Cabinet on Thursday gave Prime Minister Theresa May the green light to work with the USA and France "to co-ordinate an worldwide response", though it gave no indication of the timing or scale of any action.
After meeting for more than two hours, the Cabinet gave May the green light to join the USA and France in planning possible strikes, but also left open the possibility of other responses.
When - or if - the United States does take action against Syria, the message will be heard loud and clear in Damascus: Using chemical weapons to kill innocent people triggers a righteous USA military response. May isn't legally required to do that, though it has become conventional since the 2003 invasion of Iraq for lawmakers to be given the chance to vote before British forces are deployed. Trump and Defense Secretary James Mattis said this week they're not ruling out the possibility of a military response.
But across Western capitals opposition to military action also grew.
"I think it is important to have a common line, without Germany participating militarily", Merkel said.
The damage was intentionally limited and proportional, but it sent a message that the United States won't look the other way when a madman gasses his own people.