Pentagon: ISIS is resurgent in Syria

The report further claims that ISIS has managed to "regroup and support operations" in both countries because local groups haven't been capable of keeping the territory that they have gained from ISIS.

At the end of 2018 US president Donald Trump declared a total victory over ISIS. He also pulled out the majority of American troops that were operating in Syria.

The Syrian Democratic Forces (SDF) had warned the US president that the fight was not over and that it was not a good idea for the American forces to leave the country. The SDF are a cooperation of Western backed forces from the Free Syrian Army and Syrian Kurdish Peshmerga.

Experts on ISIS, like Hassan Hassan, director of the non-state actors program at Centre for Global Policy, predicted that Isis would make a comeback in Syria, just as the Taliban did after being driven out of Kabul in 2001.

New migration flows

The recognition by Washington of a comeback of ISIS in Syria comes at a moment of new tensions in the Middle East.

Turkey has started to deport Syrian refugees to Syria, against their will. At the same time, Turkey's president Recep Tayyip Erdogan is threatening to launch a military attack on Kurdish forces in Syria.

This Kurdish YPG militia received political support from the United States as it helped American forces in their fight against ISIS.

For many Syrian refugees in Turkey the situation is becoming more and more uncertain. On the one hand Turkey is becoming a less welcoming place. On the other hand, Syria is even less safe than it was a few months ago.

Russian fighter jets, supported by forces of Syrian dictator Bashar al-Assad and Iranian militias are bombing the remaining rebel areas in north-west Syria.

If ISIS will resurface in eastern Syria in the months to come, Syrians will choose to flee the region again, with destination Europe.

Consequences for Europe

Tensions with Iran in the Strait of Hormuz have been rising in the last few weeks. The US has asked European allies to join them in securing the world's most important oil seaway and protecting the oil tankers passing through the Persian Gulf.

The UK and Denmark have already committed to join the US, while other European countries have showed interest. The question is if these European countries will remain involved if a new war against ISIS will come back on the agenda.

Another issue is becoming more urgent too. According to the Pentagon report there would still be some 14,000 to 18,000 ISIS fighters in Syria and Iraq, of which some 3,000 foreign fighters.

There have been debates in most European countries on what to do with ISIS fighters with a European nationality. Very few European governments are keen to welcome the so-called ISIS brides (who married the fighters) and their children back to their respective countries.

On the return of the fighters with a European ID, there is even less appetite.

And then there is the question of migration to Europe. Italy's government has decided to fine boats with migrants entering Italian ports up to €1m. In other European countries there is not much political will to take in more refugees.

However, with a continuing civil war in Libya, uncertainty in Sudan the push from migrants and refugees from the south will continue.

A bigger challenge might even come from Turkey. The pressure on Syrian refugees in Turkey is increasing, while Erdogan is preparing an invasion in Syria.

If the tension with Iran are not solved quickly and ISIS will resurge in Syria, Europe will see soon a new wave of displaced refugees knocking on its doors.

For the European leadership, new and old, the summer holidays might turn out to be shorter than expected.