What are the conditions for traveling to the lands of the disbelievers?

The Shaykh : Therefore, we say that it is not permissible for any Muslim today to travel to the lands of the West, even for the sake of what they call today "knowledge," except under two conditions. The first condition is that he be protected (muhassin). There is a philosophical nuance in the expression, but it is a fine one: that he be protected by Islamic morals. As for being "muhassin" in the general sense, that is well known; this is a legal term meaning that he is married, and thereby he protects himself from any corruption from that society seeping into him, which he was compelled to go to in order to acquire the knowledge he has chosen for himself. And with the condition that this knowledge is, in the view of Islam, acceptable, prescribed, and permissible, at the very least. If we say today that it is not permissible for a Muslim to marry a non-Muslim woman, it is because this non-Muslim woman does not enter an Islamic environment where she would be stamped with its morals, because the environment itself is not Islamic. We see that we cannot raise our Muslim women and our Muslim daughters with an Islamic upbringing except in very few and rare cases, and the rare case has no ruling, as it is said. So how can we bring into our homes someone who is the furthest from our beliefs, morals, and behavior, let alone our customs? Therefore, we ask Allah (Blessed and Exalted is He) to inspire us with guidance and to grant us success in understanding the Book of our Lord and the Sunnah of our Prophet, and upon the methodology of our righteous predecessors, for they are the people whose companion does not suffer. And peace be upon you, and the mercy of Allah and His blessings.