U.S. operations supporting the Mujahedeen in Afghanistan against the Soviets were conducted almost entirely from and through Pakistan.
Notes on verification
Well-corroborated by multiple independent sources including academic/military analysis (West Point CTC), historical overviews, and Wikipedia's detailed account of Operation Cyclone, all confirming Pakistan (via ISI) as the near-exclusive conduit for CIA support to the Mujahideen. [cascade flags: wikipedia_dropped_other_sources_exist | tier=silver indep_score=0.875 clusters=2 claim_tier=notable]
Sources
- Special Warfare: The Missing Middle in U.S. Coercive ... (seed:military_and_intelligence)
- https://ctc.westpoint.edu/comparing-the-u-s-and-soviet-experiences-in-afghanistan/ (corroboration)
- https://courses.lumenlearning.com/suny-hccc-worldhistory2/chapter/the-united-states-and-the-mujahideen/ (corroboration)