They are my best friends.

His country is facing a crisis of territorial violation.

His country was sued in the International Court of Justice for the crime of violating territorial sovereignty.

Yesterday, our country's airspace was violated by the enemy nation.

North Korea has violated our country's airspace again.

That action was criticized as a clear infringement of sovereignty.

That action constitutes an infringement of our country's sovereignty.

I went around the lake on a sightseeing boat.

He is studying the history of Atakebune.

We traveled by steamship.