Considering that the US effectively stole the land for the canal in the first place, perhaps it was appropriate for the US to return it to Panamanian control. Funny how none of the "horror" scenarios about what disasters would befall us if the canal was to be returned to Panama, that were bandied about at the time, have come to pass.

For reference, to support my statement, here is a Wikipedia link to Canal history:

[en.wikipedia.org]

Also, per this link, the third channel was begun in 1940, not the 1970's.