He resigned in March 1942 to join the United States Army and served with distinction in New Guinea as a guerrilla fighter during the Japanese occupation of the Philippines. While overseas, he contracted polio which left his legs paralyzed for the remainder of his life. He went through 16 months of rehabilitation at a military hospital in Arkansas, then utilized leg braces, canes or crutches to walk. He received the Philippine Legion of Honor and the Gold Cross. In the U.S., he was awarded the Bronze and Silver Stars and was discharged as a captain in 1947.