Krähenbühl started at the ICRC in late 1991 with an assignment in El Salvador, following the ending of the civil war there. He was then posted in Ayacucho, Peru (1992–93), working in the remote Andean regions, in villages bearing the brunt of the violent confrontation between the Shining Path and the Peruvian Armed Forces. The following two years saw him working in Afghanistan, first in Jalalabad (1993), then in Kabul (1994–95).