After the fall of Homs and Aleppo to the regime, Idlib is fast becoming the latest flashpoint in Syria.

There will be major political, diplomatic and humanitarian consequences if the Bashar Assad regime takes Idlib – the last opposition stronghold in Syria.

If a conflict erupts, it will most likely be the last of the civil war. Turkey has been supporting opposition forces since 2015. Operation Olive Branch and Operation Euphrates Shield were conducted in cooperation with legitimate opposition groups. The future of the Syrian opposition is therefore very significant to Turkey.

The regime has deployed significant forces around Idlib and has been dropping leaflets, calling for the members of the opposition to give themselves up. When one considers what happened in Homs in 2011 that ignited the civil war and the rapes, chemical attacks, mass incarcerations, murders, indiscriminate aerial bombing and many other atrocities that followed, it is hard to find a single person in Syria who will believe any promises made by the regime.The first few years of the civil war were truly catastrophic, brought about by a criminal regime acting without any restraint or consideration of the law. The Assad regime believed that the only way to take back control of the country was to wage an unrestricted war on the opposition, torturing and murdering its own people. The international community preferred to sit on its hands and pontificate.

As the war became intractable and outside powers intervened, the war in Syria suddenly became institutionalized. As Turkey, Russia and Iran debate ways to put an end to the war through the Astana process, separate meetings are also being conducted by other interested parties.

In its leaflets, the Assad regime promises to be lenient on those who turn themselves in, pledging amnesty. While the opposition will likely ignore such utterances, it is hardly rational for the regime to commit atrocities with impunity as it did earlier in the war with the entire international community watching – especially after the recent U.S. and French warnings about the repeated chemical attacks.

Idlib is no longer a center of opposition that the regime wants to eradicate, unlike the other opposition cities it destroyed earlier. The province remains a trump card that every actor involved in the Syrian war wants to capitalize on.

The sides have already started to play their hands. After the U.S., U.K. and France warned the regime that they would immediately retaliate against a regime chemical attack on Idlib, Russian Foreign Minister Sergey Lavrov asked how Damascus could have any chemicals to attack with if the U.S. and France had destroyed them all in the first place.

For the 3 million civilians in Idlib, uncertainty lingers.

The regime is trying to portray those in Idlib as innocent bystanders forced to remain in the city under opposition control; however, many are people who fled regime attacks from Homs, Damascus, Latakia and Aleppo. Syrians sheltering in refugee camps in Turkey are still frightened of what Assad can do to them. They don't want to leave any social media fingerprints that the regime may be able to trace. It is unlikely that the people of Idlib can't wait for Assad to come and liberate them. If the regime occupies Idlib, rapes and murders will follow, as it has in countless towns, villages and cities across the blackened Syrian landscape.

No wonder every humanitarian official who knows what he or she is talking about is warning of an immense refugee exodus consisting of 2 million to 2.5 million people if the regime begins its assault on Idlib. The U.N.'s dire warning about what may happen has been ignored by everyone but Turkey. Operational Division Director John Ging at the U.N. Office for the Coordination of Humanitarian Affairs repeated the warning this week. He said the approaching crisis "has the potential to create a humanitarian emergency at a scale not yet seen."

We need to heed this warning. All parties that have an inkling of influence on the Assad regime need to use to abide by the cease-fire. Rather than supporting one side or another, it is time to put a stop to the impending humanitarian crisis that will intensify the already dire state of affairs in Syria and neighboring countries. The time to act is now.