The World Book entry on "Air Force" is actually several entries. There's "air force," which covers the concept of military airplane-based units generally; "Air Force, United States," which covers the US Air Force"; "air force history," which is exactly what it says on the tin; and a separate entry on aircraft used in modern air forces.
Observations, some personal, some not:
-
I did learn some interesting things about the history of air-based military maneuvers. The early use of hot air balloons to track troop movements, starting in the late 18th century, fascinated me. Imagine knowing that some dude in a balloon on the horizon was reporting to the enemy exactly where you were, and there was nothing at all you could do about it.
-
The entry lists Israel as one of the countries with a "modern air force," and it even lists the approximate number of military planes Israel has (which, per citizen and/or per square mile, is MUCH higher than the number the US has, even though the total count is much lower). It omits even the near appearance of explaining how Israel got those planes, however. That's really hard not to notice in light of recent world events.
-
It's not actually possible to read any of these entries "objectively." I didn't think it was, and I wasn't pretending to, but the air force ones made that obvious. The World Book is as straightforward about air-based military facts as it is about any other - but since they're facts I don't personally like, I found myself irked by this passage. But I learned a lot!
-
Airplanes last a lot longer than cars, apparently - the two "Air Force One" planes were put into service in 1990 and 1991, respectively. How do we get cars to last this long?
-
A thing I knew but is fun to repeat nonetheless: "Air Force One" is whatever plane the President happens to be on. The blue and white plane we think of when we think "Air Force One" is the official/preferred version, as it has a conference room and space for the President's staff and so on. (Actually, that plane is two planes.) But when POTUS is in the air, whatever plane POTUS is on is "Air Force One" to air traffic controllers. (Imagine POTUS hopping on a Cessna and the hobby pilot being like "dude, I'm Air Force One now, awesome.")
-
A thing I did not know: the Navy has planes.