Photo Gallery The Unveiling of NATO 3.0

NATO's first secretary general, Lord Ismay, described the original idea behind the alliance in this way: "to keep the Russians out, the Americans in and the Germans down." But now things have changed. The Soviet Union no longer exists, Russia is 1,000 kilometers (625 miles) farther away, and Germany no longer poses a threat. These days, NATO forces are busy in places like Afghanistan (pictured here), but are also having to combat threats that were not even imagined by its original mandate.

In a two-day summit starting Friday in London, leaders from NATOs 28 member states will convene to discuss a new strategic concept for the 61-year-old alliance. The members will have to discuss Afghan President Hamid Karzais recent calls for NATO to scale down its military operations there, but also how to deal with other threats, such as missiles from Iran and North Korea as well as cyber war.

NATO Secretary General Anders Fogh Rasmussen recently said that the alliance needs to become "more effective, more engaged and more efficient." The strategic concept represents the first overhaul of NATOs basic mission since 1999.

Russian President Dmitry Medvedev will attend a separate NATO-Russia session on Saturday. NATOs new strategic concept involves inviting Russia to take part in a joint missile-defense effort to create a missile shield over Europe, according to the Associated Press.