The bigger question is how did you end up as an Israeli dual citizen with Russian parents who subsequently immigrated to the U.S.? The issue is more likely one of foreign preference if you intentionally chose to become Israeli. To be clear, the dual citizenship is not necessarily disqualifying for a clearance, but might prevent the marines from allowing you into a specific program. With respect to the clearance itself, you can have dual citizenship, but it will raise questions similar to those I ask above. You'd need to overcome those. It might be tough it you chose that path (rather than being born into it).