The UK police and others make extensive use of 'Language Line' for telphone translation; I've only used it for prisoners in custody, when upon arrival their rights etc need to be explained (seperate arrangements for interviews). Their website is: http://www.languageline.co.uk/ (they are originally a USA based company).

Given that mobile phones now are in wider use in Afghanistan (no idea of coverage) would it make sense for a similar in-theatre set-up? Each patrol, without a "terp", can callback and get help.

davidbfpo