Baron Hastings Lionel Ismay (1887–1965) was a British soldier, diplomat, and statesman best known as Winston Churchill’s chief military assistant during World War II and as the first Secretary General of NATO. A career officer in the British Indian Army, he played a crucial role in coordinating military strategy between the Allies. After the war, he was instrumental in shaping NATO, advocating for collective defense against Soviet expansion. His legacy remains tied to his efforts in strengthening transatlantic security cooperation.