The US says it has put Syria "on notice" that it will pay “a heavy price” if it uses chemical weapons against its own people.

The White House says Syria appears to be preparing just such an attack, the latest escalation in a multisided civil war in Syria since 2011.

“A heavy price,” in this context, is widely seen in foreign policy circles as code for military action.

The Trump administration is also warning Syria's allies, Iran and Russia, that they would also be held responsible for any chemical attack.

“This is a really dangerous situation,” says Borzou Daragahi, a correspondent for BuzzFeed News in Istanbul. “It’s how big wars start, actually.”

Moscow has called the US assertions “unacceptable,” and it may not be a coincidence that Syria’s President Bashar al-Assad made his first public visit to the Russian air base in western Syria on Tuesday. Assad’s regime circulated pictures of him sitting in the cockpit of a Russian Su-35 warplane.

Syria's President Assad is pictured sitting in a Russian fighter plane during a visit to a Russian air base, Tuesday, June 27, 2017. 

Sana/Handout via Reuters 

The symbolism was obvious. The Su-35 is a fighter jet designed to intercept other warplanes, rather than a ground attack aircraft. Ostensibly, Russian forces are in Syria simply to fight ISIS, which does not have an air force.

Russia has installed and manages a fairly sophisticated air defense system in Syria, which could pose a significant threat to US airplanes.

The US also says it is only in Syria to fight ISIS. But the Trump administration launched a missile strike on an air base of the Syrian government in April, after a previous chemical attack. The Syrian government, for its part, has always denied using chemical weapons, despite verification by international scientific organizations of chemical deaths and injuries.

But the bigger context is the fact that the so-called Islamic State is losing control of its self-proclaimed caliphate and is facing military defeat in Raqqa in Syria, and Mosul in Iraq.

Newly liberated Iraqi children gesture to motorists in West Mosul, Iraq, on June 27, 2017. 

Erik De Castro/Reuters

Russia, Turkey, Iran and the US already have troops on the ground and have recruited and deployed local allies, some of whom have already confronted each other and caused casualties. Saudi Arabia, Israel and Jordan have also gotten involved, but to a lesser extent.

The defeat of ISIS could, for example, end with Iranian allies and proxies in control of a land corridor from Tehran to the border with Israel. That’s also a major concern for US ally Saudi Arabia, which is involved in a kind of Cold War with Iran for influence in the Middle East. The Saudis have been fighting Iranian-backed rebels in Yemen since 2015.

The US is also increasingly willing to confront the growing influence and regional power of Iran. In stark contrast to the Obama administration, the Trump White House has openly sided with the Saudis.

Both National Security Adviser H.R. McMaster and Defense Secretary James Mattis have written about or articulated the need to contain Iran and to contain the spread of Iranian power in the Middle East.

Daragahi says there’s the potential for a major war.   

“I don’t think anyone wants a big war,” he says. “I don’t think the Pentagon wants a big war. They want to contain Iran. They want to contain Iran’s ambitions.”

“I don’t think Iran wants a big war with the US," he adds. “They want, in their own words, to stop the spread of US influence in the Gulf region and the Middle East. They see that as a strategic threat.”

But Daragahi says the Iranians also see the various crises in the Middle East as an opportunity “to fulfill a destiny that they feel is their birthright, to some extent.”

“So, there’s a real conflict of ideological goals and strategic considerations,” he says. “Yes, we could stumble into a big, ugly war that we didn’t plan. ... And those are always the worst.”

Over the last couple of centuries or so, argues Daragahi, "the big wars have happened because of miscalculations and accidents, between the great powers, sort of stumbling into wars.”

“And this is the kind of situation we’re getting into now, with all these big powers crowded around in various corners of Syria; each trying to anticipate what the other side is going to do; each rather confident of its moral and strategic position; each poising itself for where it will take land or take opportunities or take resources, once ISIS falls.”

It’s a perilous situation, he says, which requires diplomacy, subtlety and "real communications" between the parties. But Daragahi highlights that there is very little real communication taking place. Instead, he says, “there’s a lot [of] ham-handed rhetoric on the part of both the Trump administration, the Kremlin and the regimes in Tehran and Damascus.”

No one, he says, “is speaking intelligently or wisely about it.”

If the US decided to hammer Syria, Russia could choose to allow that to happen. “I think they would probably not respond reciprocally if that were to happen,” says Daragahi. In other words, they would avoid a head-on confrontation with US military power.

“But there are other ways that Russia or its allies could respond, asymmetrically,” he adds. “They could have the Syrian regime or one of its militia proxies hit a US asset in the region, not necessarily just in Syria. So, there are ways of extracting a penalty that falls short of all-out confrontation with the US.”

There was confusion in Washington on Tuesday morning when sources at the Pentagon and in the State Department told reporters that they had no knowledge of any Syrian chemical preparations and that they were not consulted about the new threat issued by the White House.

“We’re still not clear about where the information is coming from,” says Daragahi. “Our military and intelligence contacts say they have no idea what the White House is talking about.”

But a Defense Department spokesman later echoed the White House statement.

Daragahi says the threat from the White House is being seen in the region as “credible,” despite the apparent confusion.

From PRI's The World ©2017 PRI