I travel internationally often, and usually through what are considered 'high crime' airports; Manilla, Bangkok, Jakarta, Miami, etc., and found the safest way to carry anything important is locked up inside a "Pac-Safe" travel bag locked to the inside frame of my suitcase. These bags are made with strong steel mesh sandwiched between heavy cordura nylon so are slash proof, have secure locking closures, and can be locked to other things such as the internal frames of a suitcase or backpack, or to water pipes or radiators while you are in your room or dormitory sleeping. They stop the petty thievery by airport personnel, and are great for securing your passport, cash, traveler's checks, etc. before having them locked into the hotel's lockbox or storage room. I've been using these systems for years and never lost a single item. "Pac-Safe" makes a lot of different products for travel, and some of them, such as the butt-pack that is secure against 'razor artists' on crowded busses and trains is another great item.
Stitchawl
Stitchawl