He killed the enemy with a sword.

There is no one who can rival his skills.

The issue of the Northern Territories has been debated between Japan and Russia for many years.

They are my best friends.

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

North Korea has violated our country's airspace again.

That country is suspected of violating territorial waters.

Their ship intruded into our territorial waters.

That action was criticized as a clear infringement of sovereignty.

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