I am a PhD student in mathematics in the US, scheduled to graduate this year. Last fall, I applied for postdoc positions. My situation is a bit complicated: in late January, I was offered a postdoc position in China. I wasn't particularly thrilled about this opportunity because there's no one working in my specific area of expertise at that institute, although there is no teaching load involved. Additionally, I have no proficiency in the Chinese language, and as a married individual with children, I anticipate potential challenges in adapting to life in China. Despite my doubts, I tentatively accepted the offer at the beginning of March, although no formal documentation has been signed yet, as I was informed that the onboarding process had already commenced.
The day after accepting the offer from China, I received an invitation for an interview from a university in the UK, which is where I would prefer to go because there are researchers there who specialize in the same area as I do. However, the interview isn't until four weeks from now. If I receive an offer from the UK university, I am seriously considering declining the offer from China. I understand that the academic community is relatively small, and this decision may have potential repercussions, but I question the wisdom of joining University X without a mentor and without proficiency in the local language, especially given my family situation.
Could anyone provide advice on what steps I should take in this situation?
UPD. If this somehow alleviates the situation, I am prepared to reimburse all financial expenses that have been incurred during the onboarding process. I need to emphasize that I applied for both positions at the same time, but for some reason, they took different amounts of time to reach their final decisions or schedule interviews.