Is the marriage religiously valid if a Muslim woman marries an American who claims to be Muslim, works as an officer in the American army in an Arab country, and is not seen praying? And is his work against Muslims permissible?

Prayer is a great pillar of Islam, and abandoning it is considered an act of disbelief that expels one from the faith. It is not permissible for a Muslim woman to marry someone who does not pray, nor to remain married to him if he stops praying after marriage. The importance of prayer must be explained to a husband who has recently embraced Islam; if he insists on abandoning it, a separation between them becomes obligatory. The sister's lack of concern for her brother's advice regarding her husband's prayer is strange, and she should continue to be advised, taking into account the possibility that she herself might not be praying.