Vladimir Rezun, a former officer of the Soviet military intelligence and a defector to the UK, considered the claim in his 1988 book "Icebreaker: Who Started the Second World War" under the pseudonym Viktor Suvorov and again in several subsequent books. He argued that Soviet ground forces were well-organized and mobilized "en masse" along the German–Soviet frontier for a Soviet invasion of Europe slated for Sunday, 6 July 1941 but were unprepared to defend their own territory.