Is the C++ Standard Library part of the C++ Language?

Is the C++ Standard Library part of the C++ Language? (note "language", not "standard"; both are, of course, part of the standard).

If so, why? If not, why not?

The answer to this question may differ across C++98, C++03 and C++0x.

It's not subjective because it can be inferred from wording/requirements in the relevant standards documents.