The chairwoman of the Bundestag defence committee, Marie-Agnes Strack-Zimmermann, says the recent terrorist attack on a concert hall near Moscow, which claimed more than 130 lives, is a “serious blow” to the Russian security authorities. In an interview with the Sunday edition of the Bild newspaper, Strack-Zimmermann, a defence expert from Germany’s junior coalition partner, the Free Democrats (FDP), said there had been warnings before the attacks. Western and US intelligence services warned an attack might be imminent at the start of the month, with the US embassy in Moscow calling on citizen…