The head of the Catholic Church in Portugal has advised Portuguese women to think twice before marrying a Muslim. Cardinal Jose Policarpo said late Tuesday that Christians should learn more about Islam and respect Muslims. But he said marrying a Muslim man can bring "a whole lot of trouble" because Christian women become subject to Muslim conventions. "Think twice before marrying a Muslim, think very carefully," Policarpo said in the comments broadcast widely on Portuguese media Wednesday. "You can get into a whole lot of trouble, and not even Allah knows where it might end."