He served in Silesia as an assistant (French: adjoint) of Captain Adrien Henry [fr] in the Alps, in Germany, and in Morocco at the general staff headquarters of the division of Marrakesh.

"[5] Later, Kœnig served as the Free French delegate to the Allied headquarters under General Dwight D. Eisenhower.

Under his command, the FFI abandoned ranged battle in the maquis and preferred sabotage that was waged in support of the invading army.

On 21 August 1944, de Gaulle appointed Kœnig military governor of Paris to restore law and order.

In 1951, after his retirement from the army, Kœnig was elected as Gaullist representative to the French National Assembly and briefly served as Minister of Defense under Pierre Mendès-France (1954) and Edgar Faure (1955).

[8] He gave his strong support to the new State of Israel as president of the Franco-Israeli Committee (Comité franco-israélien), at around the same time when he was France's Defense Minister, as shown from his informing his Israeli counterpart Shimon Peres that France was willing to sell Israel any weapons it wished to purchase, from small arms to tanks (such as the AMX-13 light tank).

[8] Kœnig had witnessed the heroism of a battalion of Palestinian Jewish mine layers during the Battle of Bir Hakeim and afterwards allowed them to fly their own Star-of-David flag, against British regulations.