Green’s Dictionary of Slang

a generic term for a Russian; thus a Communist.

[1899		Record-Union (Sacramento, CA) 12 Nov. 8/3: Ivan Ivanovitch (pronounced Ee’vn Eevan’ovitch), a Russian].
[1925		(con. WWI) Fraser & Gibbons Soldier and Sailor Words 129: Ivan: The everyday name in the Russian Army, at any rate down to 1916, for a private soldier].
1944		Amer. N&Q June 48: The airmen [...] began to refer to every young Russian aide as Ivan.
1952		W. Winchell On Broadway 4 Sept. [synd. col.] The U.N. has quietly bounced 13 officials known as pro-Ivans.
1989		T. Blacker Fixx 294: Get Ivan off my case.
2000		J.J. Connolly Layer Cake 235: Are these going to Moscow? Gets the Ivans and Ivanas livened up?
2021		J. Ellroy Widespread Panic 76: ‘I won’t say no to some Ivan’s Lubyanka stash’.