I am an American vet and had a TS/SCI until i separated(honorably). I want to reenlist and get a Secret, but I also want to take a little time and volunteer/travel before I go back in. Specifically, there is a Canadian NGO that does humanitarian stuff in Iraq with the Kurds. The NGO is official and is registered with Canada, but will an investigator see this and no-go my clearance?
We have U.S. personnel all over the world providing such aid, so no, that in and of itself will not prevent you from getting cleared. However, ensure you capture all relevant data about the company, your payment and benefits, travel information, and U.S. contacts that can corroborate. Once you are done ensure you break all ties as far as any responsibilities and any remaining benefits.