What does one haft to do to travel internationally?

I have a girl friend that is from the phillipines she is currently working in israel on a work visa but her work is almost up . And she wants to come visit me in las vegas for a week or two how hard or easy is this to make happen i see all kinds of foreiners visiting here in las vegas so it cant be that difficult for her to come visit and also vice versa what would i haft to do to visit her in south east asia what are the steps i would haft to take