De or het supermogendheid?

The correct Dutch article is:

de supermogendheid

Rule Words ending in -heid: almost always de. See the rule

How to use supermogendheid

the supermogendheidde supermogendheid
this supermogendheiddeze supermogendheid
that supermogendheiddie supermogendheid
our supermogendheidonze supermogendheid
your supermogendheidjouw supermogendheid
every supermogendheidelke supermogendheid
which supermogendheid?welke supermogendheid?
a big supermogendheid / the big supermogendheideen grote supermogendheid, de grote supermogendheid