Troubled Australian surprisingly into acquiring citizenship of another country (14)

'citizenship of another country' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.

'troubled australian surprisingly into' is the wordplay.
I cannot really see how this works, but
an anagram of 'australian' is 'naturalisa' which is located in the answer.
an anagram of 'into' is 'tion' which is within the answer.
This accounts for all the letters.
This explanation may well be incorrect...

'acquiring' acts as a link.

Can you help me to learn more?