The sheer volume of headlines tells its own tale. Russian drones over Poland and Romania. Russian fighter jets in Estonian airspace. Russian aircraft buzzing a German naval frigate in the Baltic Sea. Unidentified drones over Copenhagen and Oslo airports. Most recently, in the early hours of Thursday, further drones appearing at other Danish airports.

In just over a fortnight, European states have reported a striking spate of incursions into their airspace. Russia has repeatedly

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