The statistic — revealed this month by the Marine Corps Times — was another reminder of just how violent, out-of-control and complex the largely hidden war in Syria remains.

With the support of Russia, Syrian President Bashar al-Assad has secured his position and is no longer fighting for his life.

But the government in Damascus still lacks control of vast portions of the country, and a complex range of outside actors have found themselves increasingly dragged in.

Major Israeli airstrikes this week against Syrian forces, and Turkey’s ongoing offensive against Kurdish militants, were the latest indications of just how dangerously tensions have escalated.

Both Israel and Turkey had largely avoided direct involvement over the nearly seven years the Syrian war has been raging. Now both have concluded that their interests require them to get their hands more seriously dirty.

For the US, this is an awkward dynamic. Washington did everything it could to stay out of the war, now the bloodiest of the century.

The speed and scope of IS’s rise forced it to change course but, beyond defeating the militants, US president Donald Trump’s administration does not seem to know what it wants to achieve.

The US has helped the predominantly Kurdish Syrian Democratic Forces to carve out large swaths of territory. But that is ground the SDF probably cannot hold against its Turkish and Syrian government enemies without significant US backing.

Now the United States is finding itself forced to engage, though it no longer has any clearly articulated mission of its own. Last Wednesday, the US-led coalition struck pro-government forces that were moving on its allies in the SDF.

Reports suggested that as many as 100 may have been killed in the airstrikes, prompted by what the United States says was an unprovoked attack on nearby SDF forces and the handful of American troops accompanying them.

If those figures are correct, that would make it the bloodiest engagement yet between Washington and the Syrian government.

Speaking the following day, US Defence Secretary James Mattis described the strike as a matter of self-defence. Democratic Virginia Senator Tim Kaine expressed concern, however, accusing the Trump administration of “deliberately stumbling” into a broader war in Syria, without consulting Congress.

That may be overstating it — not least because there does not seem much that is deliberate about US actions.

The issue for Washington, as for most of the other major players, is that having become embroiled in the war, it finds itself forced ever deeper simply to have any hope of maintaining influence.

Still, there’s no doubt the Pentagon has been keen to hold as much of a veil as possible over events in Syria.

In December, it revealed it now had roughly 2,000 troops in the country — four times the figure previously released. The newer numbers, it said, were already a reduction from those early in the year, when the fight against IS still raged in earnest. Further withdrawals are planned, but whether they will be possible is a very different matter.

It’s a dynamic that is just as true for Russia and Iran, Assad’s primary backers, as well as a now increasingly involved Turkey.

Having come so close to losing power entirely, the Assad government clearly intends to retrieve every inch of territory it can. Having apparently concluded that a renewed co-ordination of external pressure for regime change is no longer likely, the Syrian military is once again quietly intensifying the ferocity of its onslaught on surviving rebel areas, including reported use of limited strikes with chemical weapons.

Such ongoing brutality might be enough to eventually crush some of the last rebel enclaves, primarily around Damascus. But it is unlikely to restore security to the country entirely. In December, Russian President Vladimir Putin effectively declared victory for Moscow’s military campaign in the region, pledging that some of its forces would return home.

Whether that will truly happen divides analysts. The prospect of a Russian withdrawal, however, has been accompanied by growing activity by forces linked to Tehran.

Iran had been frustrated that Russia initially seized the agenda and is keen to retain territory and influence for itself and its primary regional proxy Hezbollah.

This, of course, has inevitably antagonised Israel. This week’s strikes were prompted after a suspected Iranian drone launched from Syrian territory penetrated Israeli airspace, and intensified after an Israeli F-16 jet crashed after apparently being hit by Syrian antiaircraft fire.

Such largely accidental escalations are becoming ever easier, and could push US forces in further confrontations, not just with Syria, but with Russia and Nato ally Turkey as well.

It emerged this week that at least two Russian contractors may have been killed in the US airstrikes the previous week, a sign of just how confused and risky things may get.

For the government of Turkish President Tayyip Erdogan, the success of US-backed Kurdish militias against IS risks becoming a very different kind of disaster. The Kurdish-led Syrian Democratic Forces and their US allies now control an area roughly the size of Indiana.

The United States says its focus in Syria remains counterterrorism, but it has also pledged not to withdraw from key strongholds in the area the SDF currently controls, such as the strategic town of Manbij. Such promises — along with the creation of a border force in collaboration with the Syrian Kurdish authorities — have simply infuriated Turkey further.

In the weeks and months to come, Washington will have to work out what it realistically can achieve. Holding the terrain it currently occupies with the SDF is achievable, but could require further reinforcements in the face of Syrian and Turkish pressure.

Working with Moscow, Tehran and Ankara on a peace deal might also have merit — but in the short term, all sides appear too focused on testing their strength militarily to seriously consider such negotiations.

Don’t expect things to get better anytime soon. Syria’s long nightmare isn’t over yet, and if anything, it will continue to become more complicated.

Peter Apps is Reuters global affairs columnist, writing on international affairs, globalisation, conflict and other issues