Como dizer "Em represália a" em inglês

- In reprisal/retaliation for something

- The american military intervention in afghanistan was, in some way, in reprisal/retaliation for the terrorist attacks of september eleventh
(A intervenção militar americana no Afeganistão foi de certo modo em represália aos ataques terroristas de onze de setembro)

And by thw way guys, how about saying "The american military intervention in afghanistan was somewhat in reprisal/retaliation for the terrorist attacks of september eleventh" Can I use somewhat in this way? I'm not too confident of using it.

Thank you all and have a nice day!