"The first use of nuclear weapons must remain in the quiver of escalation as the ultimate instrument to prevent the use of weapons of mass destruction," said a 150-page analysis released in Brussels.

The commanders said the some of the key threats alliance members faced were political fanaticism and religious fundamentalism, globalization of international terrorism, organized crime and weapons movement, and the weakening of such organizations such as the United Nations, NATO and the European Union, The Guardian reported.

The authors were Gen. John Shalikashvili, the former chairman of the U.S. joint chiefs of staff, Gen. Klaus Naumann, Germany's former top soldier, Gen. Henk van den Breemen, a former Dutch chief of staff, Adm. Jacques Lanxade, a former French chief of staff, and Lord Inge, field marshal and ex-chief of the Britain's defense staff.