What is the ruling on completely or partially abandoning congregational prayers in the mosque and performing the obligatory prayer with one's wife at home, due to political tensions and a lack of feeling safe, for a resident in a foreign country?

The fatwa (definition) is that congregational prayer is obligatory for men, and it is permissible to perform it anywhere, as the mosque is not a condition. So, if someone prays in his home with his wife, his prayer is valid, but he misses the virtue of going to the mosque. If the fear for one's life is real and not merely delusions, then the worshipper is excused, and it is hoped that Allah will record for him the reward of praying in the mosque due to his intention.