I don’t know about a secret clearance. That might require citizenship. Lesser federal background checks do not require US citizenship. A TS absolutely requires

I don’t know about a secret clearance. That might require citizenship. Lesser federal background checks do not require US citizenship. A TS absolutely requires singular US citizenship. I have met many soldiers that were happy to revoke their dual-citizenship status to advance their career in the US military. I can also fully understand and appreciate why a person would not want to do that.