▁ 1 9 9 4 . ▁He ▁was ▁a ▁senior - ran king ▁Central ▁Int elligence ▁Agency ▁officer . ▁In ▁ 1 9 9 7 , ▁he ▁ple aded ▁guilty ▁and ▁was ▁sent enced ▁to ▁more ▁than ▁ 2 3 ▁years ▁in ▁prison . ▁ ▁December ▁ 1 9 9 6 : ▁Earl ▁Ed win ▁Pitts ▁was ▁charged ▁with ▁providing ▁top ▁secret ▁documents ▁to ▁the ▁Soviet ▁Union ▁and ▁then ▁Russia ▁from ▁ 1 9 8 7 ▁until ▁ 1 9 9 2 . ▁In ▁ 1 9 9 7 , ▁he ▁ple aded ▁guilty ▁to ▁two ▁counts ▁of ▁esp ion age ▁and ▁was ▁sent enced ▁to ▁ 2 7 ▁years ▁in ▁prison . ▁ ▁June ▁ 2 0 0 0 : ▁George ▁Tro f im off , ▁a ▁natural ized ▁US ▁citiz en ▁of ▁Russian ▁parents , ▁was ▁arrested ▁for ▁sp ying ▁for ▁the ▁Soviet ▁Union ▁and ▁Russia ▁since ▁about ▁ 1 9 6 9 . ▁Having ▁retired ▁as ▁a ▁colon el ▁in ▁the ▁United ▁States ▁Army ▁Reserve , ▁he ▁was ▁the ▁highest - ran king ▁military ▁officer ▁ever ▁accused ▁of ▁sp ying . ▁He ▁was ▁conv icted ▁and ▁sent enced ▁to ▁life ▁imprison ment . ▁ ▁October ▁ 2 0 0 0 : ▁Serge i ▁Tre ty akov , ▁an ▁SV R ▁officer ▁working ▁under cover ▁at ▁the ▁Russian ▁UN ▁mission ▁defect ed ▁to ▁the ▁United ▁States ▁with ▁his ▁family . ▁ ▁February ▁ 2 0 0 1 : ▁Robert ▁Philip ▁Hans sen ▁was ▁arrested ▁for ▁sp ying ▁for ▁the ▁Soviet ▁Union