by president biden. so i think it is very interesting to see these two men shoulder to shoulder now in the face of russian aggression. and if vladimir putin was hoping to exploit western divisions that actually the invasion of ukraine has brought the west much closer together. and seeing president biden here in warshaw giving a key speech in the country that was behind the iron curtain, part of the warsaw pact, is very much a sign of unity in the face of kremlin aggression. in one of its largest military exercises in recent years, nato has been simulating its response to an attack on a member state. it's been taking place in norway, which shares a border with russia and was planned before the invasion of ukraine. but as our defence correspondent jonathan beale reports, the war has given the training a sharper focus. gunfire. another neighbour of