A week after the collapse of the Assad regime in Syria, a post-Assad era may begin to emerge but it is far from certain what form that will take.

Hayat Tahrir al-Sham (HTS), the dominant faction among Syrian rebels, has transplanted its rule from Idlib Province to governance in Damascus, progressively taking the key cabinet posts for its own people. The group is certainly beginning the process of restoring public administration and order but concerns are already being raised over the speed and extent of its takeover of government.

There remains a widespread optimism that a period of calm may unfold during the three months of interim rule by HTS, which is led by Ahmad al-Sharaa. By the end of that period, it is hoped that a more representative government will emerge from across the many confessional and ethnic groups that make up Syria.

At a time of widespread euphoria, there are other views, some from highly experienced academics who are suspicious of HTS's intentions, such as Gilbert Achcar of the Centre for Palestine Studies at SOAS University of London.

In a recent blog post, Achcar reminds readers that all was far from well in Idlip, the small area of Syria that HTS already directly controlled. He said: "The residents of the Idlib region themselves demonstrated only eight months ago against HTS's tyranny, demanding the overthrow of al-Julani, the dissolution of his repressive apparatuses, and the release of detainees in his prisons."

While most Western media attention has focused on the internal state of security and well-being in Syria, as important in the longer term will be the roles and intentions of foreign states, especially five external players. Two of these, Russia and Iran, have seen their influence collapse, whereas for the other three - Turkey, the United States and Israel - their influence and direct power has grown.

Russia may have the least room for manoeuvre after its major role in bolstering the Assad regime, especially during and since the siege of Aleppo between 2012 and 2016. Moscow is reported to have reduced its air power in Syria to no more than 15 planes, stationed at a single air base, and moved its naval flotilla out to sea from its base in the Syrian port city of Tartus.

It will still want to work with the new Damascus regime, whatever form that takes, and there are reports that informal talks have already begun. Russian president Vladimir Putin may be prepared to make some major concessions to HTS because the base in Tartus gave it a Mediterranean port and a surviving toehold in the wider Middle East.

The loss of influence for Iran is much more problematic and has no easy answers. Its theocratic leadership will feel much more exposed and will almost certainly take rigorous steps to control dissent. It will also want to focus on retaining links in Syria that may have survived the Assad downfall as well as building new links.

Separately, Iran may also continue to expand its production of 60% enriched Uranium at its Fordow plant, just outside the northeast Iranian city of Qom. That level of enrichment is getting close to weapons-grade purity (90%) and the International Atomic Energy Agency has recently warned that Iran is in a position to further increase production at least seven-fold.

Of the international actors that stand to gain most from the collapse of the Assad regime, Turkey already has considerable influence in northwest Syria, particularly military influence through the Turkish-backed Syrian National Army. Turkish support for HTS was reportedly crucial in enabling it to engage in its successful coup attempt, so Ankara will at least be able to maintain its influence in the short term.

What is far less certain is the security of a large part of northern and eastern Syria known variously as Rojava or the Autonomous Administration of North and East Syria. Rojava has earned a reputation for effective governance and a substantial degree of stability and accountability, dependent in part on two powerful paramilitary groups, the People's Protection Units (YPG) and the US-backed Syrian Democratic Forces (SDF).

Where it is vulnerable is that the Turkish government regards the YPG and SDF as entirely unacceptable, seeing them as extensions of the Kurdish Workers Party, a long-banned organisation within Turkey. This extends to Ankara ordering its own military units to destabilise elements of Rojava where possible.

Then there is the United States, which had far more involvement within Syria during the Assad era than is commonly realised. This originated in the bitter war against ISIS from 2014 to 2018, when US, French and especially Kurdish forces defeated ISIS in 2017. Since then, the US has maintained garrisons totalling almost 1,000 troops and many hundreds of contractors at small bases across eastern Syria, right down to al-Tanf on the Iraq and Jordan borders.

While ISIS is a shadow of its former self, it remains active with plenty of paramilitary supporters and has engaged in attacks on regime targets. In turn, it has been repeatedly targeted by the US Air Force and US Special Forces. Last Sunday, in the wake of Assad's downfall, the Pentagon ordered a substantial air attack on ISIS that hit more than 75 targets in five different locations, using F-15 strike aircraft, A-10 'Warthog' ground attack aircraft and even B-52 strategic bombers.

Whatever else happens, it is well-nigh certain that the United States will maintain military forces in Syria, both to try and contain ISIS and also to limit any Iranian resurgence.

The final and most substantial foreign actor is Israel, which has engaged in air attacks in Syria for years, mainly directed at facilities linked to Hezbollah. In barely a week it has massively increased its operations, including its ground forces taking over the buffer zone between the Golan Heights and the rest of Syria. Israel's 1981 annexing of the Heights was against international law but the sheer amount of armour that has been moved into the buffer zone suggests that further annexing is planned, possibly even extending further into Syria.

More generally, in the past seven days, Israel has engaged in numerous air strikes right across Syria, with 350 targets hit in the first 48 hours of the post-Assad era alone. The small Syrian navy has been destroyed, and airbases, aircraft, weapons and materiel dumps bombed.

The attacks are continuing daily and go far beyond any interference in Hezbollah's capabilities. Israel most likely has two larger aims, one being to severely limit any post-Assad regime's ability to have a substantial military capability. The other is to demonstrate once again to Iran and indeed to the US that Israel has overwhelming air power to employ against Iran whenever necessary.

Given Donald Trump is about to move into the White House, it would be wise to see what Israel is now doing in Syria as a prelude to action against Iran, especially its nuclear weapons programme.

From openDemocracy