As early as mid-May 1940, while the Battle of France was still being waged, the British Government began to fear that Germany would immediately launch an invasion of the British Isles. This fear was compounded by, as historian Paul McMahon commented, the "catastrophic Allied defeats" that soon followed, which produced "two hysterias in the summer of 1940: first, fear of imminent invasion and, second, a 'fifth column panic'." The initial fear of invasion was aroused by the alleged capture of German documents, by the Dutch, which contained plans for a German invasion as well as information regarding a simultaneous attack on Ireland by paratroopers who were to be assisted by the Irish Republican Army (IRA). This document, which no longer exists, caused panic within the British Government. The information was reinforced, in the following months, by reports warning of a German intent to invade Ireland from diplomatic missions and the Secret Intelligence Service (SIS). On 14 May, following his return to the United Kingdom, Carton de Wiart resumed command of the 61st Infantry Division; Schreiber had left the division two days previously, to take command of the 45th Infantry Division. After the British Expeditionary Force (BEF) was evacuated from France, the British acted on the rumours of the German intent to invade Ireland, and the decision was made to reinforce the garrison (the 53rd (Welsh) Infantry Division) by deploying the 61st Infantry Division; in the ensuing 12 months, the division would be followed by the 5th and 48th (South Midland) Divisions and the 71st and 72nd Independent Infantry Brigades).