There are many ways to divide the world. But when it comes to military might, we divide it between those who have nuclear weapons and those who don't.
Due to the advances of nuclear science over the last half century, the eight or nine "haves" are an elite club of nations with almost 30,000 nuclear weapons and the ability to blow the earth to bits many times over.
The "have-nots" are the rest of the world -- countries who either lack the technical capacity to make atomic weapons, do not want them or are staying true to a vow never to acquire them. Some have security agreements with members of the nuclear bomb club and do not need what is usually called "The Bomb."
Then there are the "have-nots" who envy the power and respect the "haves" enjoy and are working secretly to join the club. This is how the US views Iran and North Korea.
While the US says North Korea has admitted to having made a bomb, no one has seen it. In contrast, Iran vehemently denies it wants nuclear arms and insists its atomic program is dedicated to peaceful generation of electricity.
But, Washington argues, that is what Iraq always said before UN weapons inspectors uncovered then Iraqi president Saddam Hussein's ambitious secret weapons program in 1991, the world's biggest nuclear shock since the 1986 Chernobyl accident.
As Iranian officials deny they have a secret nuclear bomb program, unsettling facts about Iran's nuclear capacities continue to surface.
This month, diplomats said that inspectors from the UN International Atomic Energy Agency (IAEA) found traces of enriched uranium in an environmental sample taken in Iran.
While this could be due to contamination, it could mean Iran has been enriching uranium without informing the IAEA, which experts say would be a violation of the 1968 nuclear Non-Proliferation Treaty (NPT), which Tehran has signed.
"If the samples confirm that Iran has enriched the uranium itself, it would mean that Iran has violated its treaty commitments," said Jon Wolfsthal, of the US-based Carnegie Endowment for International Peace think-tank.
Enrichment is the purification of uranium to make it useable in nuclear fuel -- or in weapons.
US President George W. Bush has vowed that he will not let Iran get The Bomb. Last month, a senior member of the Bush administration said military action to stop Iran from getting a nuclear weapon "has to be an option."
Some analysts say that while the Bush administration makes clear they will never let Iran get nuclear weapons, it shows no interest in addressing Tehran's very real security concerns.
Earlier this month, IAEA chief Mohamed ElBaradei told an audience in Rome that the international community must concern itself with the "demand" side of nuclear proliferation.
"We must address those chronic disputes that create the greatest incentives for acquiring WMD [weapons of mass destruction]," ElBaradei said.
"It is instructive that the majority of suspected efforts to acquire WMD are to be found in the Middle East, a hotbed of instability for over half a century," he added.
Harald Mueller, executive director and head of disarmament research at the Peace Research Institute of Frankfurt, a think-tank, said one should look at the Middle East from Iran's perspective to understand why it would want a nuclear weapon.
"Iran has good security reasons to be worried and to look for a deterrent," Mueller said. "It was attacked [by Iraq] in 1980 ... It was attacked with chemical weapons without the international community helping."