What exactly do you mean by 'successful' in this context? Are we speaking out of a conventional perspective (i.e. the elimination of enemy combatants) which is more aligned to the US doctrine in the field or are we speaking out of a more unconventional and counterinsurgency perspective (i.e. setting up militia, providing healthcare to hamlets, etc.) which was not the US doctrine but was still carried out in limited basis (the Green Berets did so in the first half of the 1960's).