Back in the United States he taught cartography, then became Inspector-General with the 2nd Division. Now a major, he returned to the War College Division in July 1915. He found that there was a general apathy about intelligence-gathering, and the MID had been downgraded from the second division of the General Staff, and merged with the third division, ending its separate identity. Van Deman wrote a history of MID detailing its beginnings in 1885, its rise in 1903, and fall in subsequent years. He was convinced that the Army must have a coordinated intelligence organization if it were to avoid defeat in the near future, especially as it was now obvious that the U.S. would soon be involved in the war in Europe. Eventually Van Deman was able to get an audience with the Secretary of War to present his case. There he convinced the War Department to accept his idea of an intelligence department for U.S. forces. A crucial role was played by Colonel Claude Dansey of the British Security Service in proposing similar ideas to Colonel Edward M. House, a member of an American liaison mission to Britain and one of President Wilson's advisors.
