When I coached soccer, I spent the bulk of the time teaching defense. I know all of these players, who have ascended to this level, are skilled and have been taught proper defending techniques. In other words, I'm sure they know what to do. Yet...they seem to forget during matches.
It's quite simple, really: mark up goal side and do NOT allow the player you are marking any space. That's it!
Except, for the USMNT, our back 4 seem to have brain farts and allow attacking players to create space. Happened several times last night. With just a little bit of luck, Honduras could have/should have scored 3. Against quality strikers, the US gets burned often.