David Lloyd George appointed him to the unpaid position of director of munitions in Scotland in July 1915, he joined the Air Board in December 1916 and was made a Knight Bachelor in February 1917. He joined the Air Council in November 1917 and became its President in April 1918, resigning in December that year after the end of the war. He was appointed to the Privy Council in April and was raised to the peerage as Baron Weir, of Eastwood in the County of Renfrew, in the summer.