Ukraine may lose the fortress belt: what the exit from Donetsk threatens.

According to a report from the Institute for the Study of War, if Ukraine agrees to Russia's demands and exits the Donetsk region, Russia is likely to violate any peace agreement and resume military aggression against Ukraine in the future.

What would full Russian control of Donetsk give?

Experts believe that this would provide Russia with a favorable position for attack, avoiding a prolonged struggle for territory. Furthermore, they argue that Russia may violate any peace agreement and resume military aggression if the agreement does not include reliable monitoring mechanisms and security guarantees for Ukraine.

The 'fortress belt' of Ukraine - what is known

Analysts note that the 'fortress belt' has been a major obstacle to the Kremlin's territorial ambitions in Ukraine. This line consists of four large cities and several towns that create a defensive belt in the Donetsk region.

Ukrainian forces have maintained control over these cities since July 2014, after repelling them from pro-Russian forces that attacked them in 2014.

The Presidents of the U.S. and Ukraine have expressed differing views on peace agreements and territorial exchanges as part of the resolution of the conflict in Ukraine.