Police have arrested people in Greece and France. One is a Greek air force officer. Two others are Chinese citizens. They may have given secret military information to China. These arrests happened together. This makes defense groups worried. It shows a security problem.
In Greece, Colonel Christos Flessas was arrested. He worked with NATO information. He might have taken pictures of secret papers. He may have used a device to send data to China.
In France, two young Chinese men were arrested. They are accused of trying to get military data. They used a big antenna in their garden. French police took many electronic things.
These arrests suggest China wants more information. The Greek minister said rules need to be stronger. These arrests are important. They show spies are still a threat.