From what I understand, とは can be used to "define" things. So does this mean
that it can be used to expand on what comes before とは/というのは and that which
comes after will explain the speakers view/opinion/etc on what comes before?

So how does it work in the example where the speaker has been called out to an
emergency meeting without being told what it was about and says

> 「緊急招集とは、おだやかではないな」
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2015-06-25T18:06:59.377
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2019-02-06T11:31:46.590
2015-06-28T06:29:24.210
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question
meaning particles
The usage of とは in 緊急招集とは、おだやかではないな
> 「[緊 急 招 集]{きんきゅうしょうしゅう} **とは** 、おだやかではないな。」
>
> = "An emergency call-out is pretty disquieting, isn't it?"

This 「とは」 is _**not**_ for defining something. Both speaker and listener know
exactly what 「緊急招集」 means already.

This 「とは」 is to express a surprise, anger, excitement, etc. It is like an
emphatic kind of topic marker. _**You did not expect it coming.**_
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2015-06-26T00:12:53.837
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2019-02-06T11:31:46.590
2020-06-17T08:18:27.500
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answer