Now Australia wants to know specifically what U.S. means by its Asian Pacific PIVOT?

When Julia Gillard was PM of Australia she with enthusiastic alacrity and perhaps unseemly celerity leaped at the chance to invite the U.S to station troops in Australia as part of the U.S's Asian PIVOT.

Now, following Chuck Hagel's denunciation of China's controversial claims over two sets of islands, the Paracels and the Spratlys, Australia wants to know specifically what PIVOT means:

http://www.theguardian.com/world/2014/jun/11/pm-advised-to-seek-clear-answers-about-australias-role-in-us-asia-pivot

It is now 2014 and WW II ended in 1945. What is the U.S. doing with its WW II military bases in England?

Well, now that the Australia have U.S. troops stationed there, it means the U.S, has a military base there.

Question:
Even at the very height of the Cold War, did Canada never invite the U.S. to station ground troops in Canada.

Here is Wikipedia's list of U.S. bases domestic and overseas. It is to say the least  IMPRESSIVE.