I recently completed a 30-day stay in the United States for a research conference and returned to Russia 14 days ago. I am now required to travel back to the U.S. next week for a secondary collaborative project.
Given the short interval between visits (14 days out after 30 days in), what is the calculated risk of entry refusal? Is there a theoretical limit or specific ratio of time spent outside the country that I must observe to prove I am not residing there de facto? I have my return ticket and documented proof of employment in Novosibirsk.