near the close of world war ii, as american, british, and russian military forces were closing in on berlin, riehl and some of his staff moved to a village west of berlin, to try to assure occupation by british or american forces. however, in mid-may 1945, with the assistance of riehl's colleague karl günter zimmer, the russian nuclear physicists georgy flerov and lev artsimovich showed up one day in nkvd colonel's uniforms. the use of russian nuclear physicists in the wake of soviet troop advances to identify and “requisition” equipment, materiel, intellectual property, and personnel useful to the russian atomic bomb project is similar to the american operation alsos. the military head of alsos was lt. col. boris pash, former head of security on the american atomic bomb effort, the manhattan project, and its chief scientist was the eminent physicist samuel goudsmit. in early 1945, the soviets initiated an effort similar to alsos (russian alsos). forty out of less than 100 russian scientists from the soviet atomic bomb project's laboratory no. 2 went to germany, austria, and czechoslovakia in support of acquisitions for the project.