The X Committee, previously described as a device Lloyd George created to plot future British strategy, held its first meeting on May 15, 1918. There was an awkward moment in the proceedings when Milner implied that Lloyd George should issue a statement, correcting the figures he had used about the combat strength of the British army during the Maurice debate. It had just come to the secretary of war's attention that the original figures supplied by the War Office were inaccurate and he wanted the prime minister to set the record straight. Lloyd George replied curtly that he could not be held responsible for an error made in Maurice's department and, as far as he was concerned, the matter was closed. Milner was a man of high integrity – a rare virtue for a politician – and he was obviously dismayed by the prime minister's cynicism. But he should have known by now that for Lloyd George to admit publicly that he had made a mistake would have been out of character. The relationship between the two men was never the same again and, in fact, went from bad to worse because of Milner's changed perspective as secretary for war.

Milner had been one of Lloyd George's most dependable allies in the War Cabinet, particularly in confrontations with soldiers over strategic policy, but his allegiance shifted when he assumed charge of the War Office.