Howard was awarded his first Military Cross while serving with the 2nd Battalion, Royal East Kent Regiment, during the Arab Revolt in Palestine in 1936. His platoon, while on internal security duties, came under heavy fire near Tarshiha and despite being injured his action led to the assailants being forced from their position on a hillside. He was seconded to the King's African Rifles and served in the East African campaign against the Italians in Kenya, Somaliland and Abyssinia, where he was mentioned in despatches. Howard rejoined the regiment in 1941 and served with the 1st Battalion in the Western Desert campaign in North Africa. He was awarded his second Military Cross for leading an attack on the night of 21 January 1943 down the Tarhuna Pass towards Tripoli which succeeded in driving the enemy back two miles. He later attended the Staff College at Haifa.