Donald Trump’s announcement that he is pulling troops out of Syria is another example of the New York property developer turned president's decision-making style. If you don’t understand or don’t like the deal, then get out of it. All that matters is the bottom line.

In business this may make sense. But in foreign policy, this type of capricious decision-making can do long-term damage to the United States.

Whether Trump’s decision to unilaterally withdraw within 30 (or perhaps 100) days is actually realised is not certain.

Whether Trump’s decision to unilaterally withdraw within 30 (or perhaps 100) days is actually realised is not certain. What is certain is that some of his senior advisers will be seeking to have the President modify his rather unambiguous direction. People intimately involved in the Syria issue have been talking about the need to ensure the “enduring” defeat of Islamic State (ISIS), while the President has now declared ISIS defeated and that it is time to move on.

Exactly what “moving on” means will become apparent in the months ahead. Trump has never liked the idea of troops in Syria, and he accelerated the military component of the anti-ISIS battle in order to declare victory and leave. So in one sense, he is being consistent with his long-held view of the utility of troops in Syria.

But there are obvious ramifications in such a rapid exit. It is worth looking at a few of the issues to address some of the claims about the second-order effects of this decision.

The Kurdish issue

Many will claim that the Kurds are being abandoned and were simply used. The reality is that ISIS was a threat to the Kurds and they had a shared interest with the West in defeating them. This could not have been achieved without US assistance.

Washington had always told the Kurds their relationship was only transactional, which is why the Kurds have been in discussions with Damascus about their long-term future. A rapid US withdrawal, however, severely weakens the Kurdish bargaining position with respect to Damascus.

The Iranians

Nobody has ever made the case for why a US presence was needed to stop a mythical Tehran-to-the-Mediterranean land corridor. Such a corridor would have been complex to maintain and highly insecure, especially when the Iranians have operated a highly successful air bridge for decades.

Iranian influence in Syria is certainly higher than it was before the civil war. But there are significant limits on Iran’s freedom of action that have nothing to do with the US. Being both Persian and Shi’a, Iran has no natural constituency within Syria, and the Iranians have to compete with Russia (militarily, politically and economically), China and Turkey (economically), and Syrian nationalists. The Israelis also aim to limit Tehran’s military activity.

The regime

The big winner from Trump’s announcement is the Bashar al-Assad regime. It simplifies the political situation for Assad, and if the regime can get its hands on the gas and oil resources in the east it will benefit economically as well.

The regime’s approach to combating ISIS remnants will be keenly watched. There is also likely to be a mad scramble between the Arabs and Kurds in the east and northeast to clarify relations with Damascus and to cut the best deal possible. The regime’s ability to deploy troops to this area in any great numbers is questionable, but as the fighting has dissipated elsewhere, there is more freedom to move forces around.

The Russians

The Syria question was always relatively easy for Vladimir Putin once he decided the cost was worth it. A half-century alliance relationship with Damascus to protect, a binary problem to solve (Assad regime good, everyone else a “terrorist”) and an understanding of the operating environment thanks to decades of military advisers passing though the country and years of fighting Islamists in Chechnya meant that Putin appeared decisive and committed compared to Washington, which faced a much more difficult problem.

Yet it would be a mistake to think that America's withdrawal will necessarily lead to an increase in Russian influence in the Middle East more broadly.

The Turks

Until recently, President Recep Tayyip Erdogan has had a tin ear to advice on Syria and paid dearly for it. By not cracking down early on jihadis traveling through his country, he suffered both terrorist blowback and marginalisation diplomatically.

The presence of Turkish forces and pro-Turkish militias close to US troops in the northeast of Syria was a potential disaster and Erdogan's threats to advance east of the Euphrates was another problem for Washington. So the departure of the US will be heartily welcomed by Ankara.

How this plays out with Damascus’ and Moscow’s attitudes towards the Kurds will be one of the more interesting issues to unfold in the coming months.