Who became Secretary General of NATO after Javier Solana?

Explanation

NATO (North Atlantic Treaty Organisation)is an international organisation for political and military defense cooperation in the North Atlantic. The cooperation was first established in 1949 and back then consisted of 12 member states. Since then, the Organisation has been enlarged in several rounds. One of these was in 2004, when a range of the former Warsaw Pact countries were admitted. George Robertson is a British Labour politician, who was Secretary General of NATO from 1999 to 2004. From 1997 to 1999 he served as the UK defence minister.