The word realpolitik should be accepted by Microsoft Word.

[TJ]

Microsoft Word's dictionary does not include realpolitik. It should.

Merriam-Webster:
Main Entry: re·al·po·li·tik
Pronunciation: rA-'äl-"pO-li-"tEk
Function: noun
Usage: often capitalized
Etymology: German, from real actual + Politik politics
: politics based on practical and material factors rather than on
theoretical or ethical objectives

 

[Suzanne S. Barnhill]

The word will be accepted if you add it to your custom dictionary. No
spelling checker dictionary ever contains every word that is in a printed
dictionary.