It's potentially more productive to invite Russians to co-operate with the U.S. while retaining their own citizenship. From personal experience, the frustratio

It's potentially more productive to invite Russians to co-operate with the U.S. while retaining their own citizenship. From personal experience, the frustrations and time lost to IRS paperwork (and resulting ennui about being a U.S. person/citizen) compared to regimes elsewhere in the world can lead to questions of doubt.