Comment: I'm sorry,

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In reply to comment: Jill, you must understand (see in situ)

I'm sorry,

but I don't think the Secretary of Defense would confuse a plane with a missile.
No-one who wasn't "in the loop" made those words interchangeable.
I haven't heard one fireman nor eye witness on that day interchange those two words. No-one said they saw missiles slamming into the WTC, when they actually meant planes.