Now, as the war grinds on in its sixth week and peace talks between Ukrainian and Russian negotiators continue, Zelensky faces a new set of challenges. He must keep up morale and the will to fight amid battlefield casualties, economic devastation and vast civilian suffering. He must retain the confidence of Western nations that Ukraine can prevail to ensure weapons keep flowing.

But as time goes on he must also figure out what if any sort of political agreement with Moscow to end the war will be acceptable to a Ukrainian population riding high after repelling Russian forces in many areas and feeling inspired to resist by his own actions and words.

“He has relied on intense feelings of nationalism to continue to fight this war, but those are exactly the forces that make it extremely difficult to put this war to an end,” American University political science professor Keith Darden said, noting that it’s unclear how long Ukraine can keep up the fight. “That’s the real dilemma in my mind.”