So basically we got "raided" because Sky Haven participated in the hold of Solidarity, which used to be a NSLeft run frontier. The thing was however that due to TCB's involvement in Solidarity it was considered a legitimate target for military actions.
It doesn't really matter as the puppet storage is just a side project anyways.
I would like to stress however that this was not a result of any IRL political ideologies but rather gameplay (raiding and defending and related stuff). While it's perfectly fine for regions to build up on a theme based on real life political ideology, once a region steps into the gameplay sphere, they aren't "protected" by their rl ideology even if I might personally agree with it. For example I am a leftist irl and have enjoyed talking to people who are members of NSLeft regions, but given TCB's participation in raiding/griefing of regions, and Sky Haven's association with defenders moreso than raiders, we participated in a defender-led military operation in Solidarity.
Someone involved in the operation likely kept an eye out for when our storage's founder nation would CTE and swooped in at the right moment.
Also Sky Haven has by design left-leaning/liberal tendencies, so I do hope those involved in the NSLeft community aren't under the impression that we participated in Solidarity due to some anti-leftist bias.