What if you're issued a boarding pass from another country where middle names are not common?

Let's say my real name John Adams Smith
My passport says John Adams Smith
My boarding pass issued by JL says SMITH/JOHNA (no middles names in Japan, no section to enter in middle names on their reservations systems, middle name trunkated to first letter combined with first name)

Or what about long middle names?
Let's say my real name is George Herbert Walker Bush.
Boarding pass shows BUSH/GEORGE HERBE

There's so many things that can go wrong here it's stupid. But then again, we're talking about the TSA