4 Finally, the US remains committed to an effective missile defence system to defend against emerging missile threats, such as from Iran and North Korea. In Europe our approach was embraced by Nato at the Lisbon summit, and it paves the way for missile defence co- operation between Russia and the US, enhancing the security of both nations, and Europe. Standing in Prague two years ago, President Obama said some believe “we are destined to live in a world where more nations and more people possess the ultimate tools of destruction”. But he also warned that “such fatalism is a deadly adversary”. Two years on, it is clear that, when the international community works together to meet a shared threat, progress is possible. We remain confident that if this momentum is sustained, a world where fewer nations possess these ultimate tools of destruction is within our grasp. The writer is national security adviser to President Barack Obama. HOUSE_OVERSIGHT_023490