The dream of a world without nuclear weapons animates millions of people across the planet. Critics deride them as hopelessly naive idealists with no appreciation of the realities of power and the way the world really works. The award of the Nobel Peace Prize last week to the International Campaign to Abolish Nuclear Weapons (ICAN) is a victory for the dreamers, a validation of the meaning and purpose behind the pursuit of the improbable — if not the impossible: the abolition of nuclear weapons.

ICAN was formed in 2007 on the proposal by the International Physicians for the Prevention of Nuclear War, which won the Nobel Peace Prize in 1985. The group built on its success by launching grass-roots anti-nuclear movements worldwide. Today, it has 468 partner organizations in 101 countries.

Since its establishment, ICAN has made a treaty banning nuclear weapons its top priority and began to press that agenda at the 2010 Nuclear Non-Proliferation Treaty (NPT) review conference. The campaign has two purposes: first, and most obviously, to create the legal basis for making the possession and use of such weapons illegal. Second, ICAN seeks to shift the nuclear debate and allow non-nuclear weapon states — the overwhelming majority of countries — to drive the discussion.