I hate to say it, but their responses, especially the bus analogy, seems very clear to me.

*DISCLAIMER* I am low on the science in this, but feel I have a working grasp of common sense so I'll try and give this a shot.

EDIT: I see that a faster, less verbose individual has posted while I was writing this. Glad to see that I'm more or less on the same page. Read on for a wordy analysis of my own

This is a matter of relativity, I think.

Bus - moving forward East to West
Person A - walking to back of bus (East)
Person B - walking to front of bus (West)
Tennis Ball - back and forth (East & West)
Observer - stationary on ground outside

To an observer on the ground watching the bus go by, the two people on board, and the tennis ball would *appear* to cover different ground distances at different 'speeds' *relative to the ground observer.* That is, Person A, when walking to the back of the bus would appear to the observer to be moving slightly slower than the bus. Person B, while walking toward the front of the bus would conversely appear to the observer to be moving slightly faster than the bus. The tennis ball, when thrown, would behave the same way, but even more pronounced.

On the bus, everything would seem to be equal between the two people. They would feel unaffected by the movement of the bus. But to the outside observer, the ground distances and speeds would be *apparently* different.

So, back to 'reality'... the airmass the planes and missles are flying in contains them. This whole 'package' is moving relative to the ground... which is irrelevant, except as a matter of observation. Within the air mass, the two planes are closing, as are the missles, all being equally, and to them, unnoticably affected.

Ok... now I get even more sketchy here, so please forgive if I am way off in my notions. Imagine two planes closing, each at 200mph. Their closing speed would be 400mph. If they fire missles at one another, those would be closing even faster. Now, imagine a 20mph wind, blowing along the same axis the planes and missles are flying along. To an observer on the ground, the plane flying into the wind would appear to have an airspeed of 180mph (powered airspeed minus wind speed), while the plane with the tailwind would appear to be moving 220mph (powered airspeed plus wind speed). Missles would be similarly affected. However, despite what this would look like from the ground, the two planes would still maintain a closing speed of 400mph, and the pilots would not register any difference relative to one another. The firing of missles would therefore appear to them to fly as far and as fast toward their targets as if the wind were still.

I dunno if this helps any. It's how I understand it. I could be off the deep end