Traveling Internationally

What do you believe is the most challenging part of traveling internationally and why?

I believe that the cultural differences are the most challenging part of traveling internationally. Business customs and etiquette can differ greatly from country and country.  Business people must be aware of these differences and educate themselves on what is or isn't proper in the country they're visiting.  This may be hard to do since the business person will have to now think through something that is normally routine for them.  For example, a firm handshake in the U.S. is expected in a business setting.  However, in some countries such as Turkey, a grip which is too firm is considered rude.  In the U.S., a business person would never dream of arriving late to a meeting.  In some cultures though, being late is expected.