He died in the 2010 Polish Air Force Tu-154 crash near Smolensk with the President of Poland Lech Kaczyński.

In August 2003, he returned to UNDOF after being appointed by then UN Secretary General Kofi Annan as its head of mission and force commander.

[3] On 27 February 2006, Gagor was made Chief of General Staff of the Polish Armed Forces upon appointment by the President of Poland.

Along with Krzysztof Paszkowski, he wrote the book: "Defense Doctrine of the Polish Republic for Peacekeeping Operations."

Gen. Gągor is an author of numerous articles and publications on military affairs and co-operation, defence transformation and armed forces modernization.