Afghan Journal | Analysis & Opinion | Reuters.com In conducting a raid deep inside Pakistan to take out Osama bin Laden, the United States pushed the boundaries of military operations, inter-state ties and international law, all of which are the subject of a raging debate in the region and beyond. One of less talked-about issues is that the boots-on-ground operation by the U.S. Special Forces also blows a hole in a long-held argument that states which have nuclear weapons, legitimately or otherwise, face a lower chance of a foreign strike or invasion than those without them. Thus the United States didnâ€™t think twice before going into Afghanistan within weeks of the September 11 attacks or striking against Libya now because there was no nuclear threat lurking at the back of the mind. Even Iraq was a more tempting target because it was not known to have a well-established nuclear arsenal although the whole point of the invasion was that it had weapons of mass destruction. That only turned out to be untrue. And conversely there is a belief that the United States or some of the other Western powers such as a newly-assertive France wouldnâ€™t take on North Korea because of the nuclear weapons it holds. It is simply too dangerous and even in the case of Iran those who favour action say the time to do it is now while it is still developing the weapons, not when it has completed the programme. But the May 2 raid in a compound in a Pakistani garrison town tests that logic and shows the limits of nuclear deterrence, as Elbridge Colby, who served recently in the office of the U.S. Secretar of Defense on START negotiations wrote in Real Clear Worldâ€™s Compass blog. Pakistan has a powerful nuclear arsenal, growing at a rate that will make it the fourth-largest in a decade behind only the United States, Russia and China. It has the delivery systems, both missiles and aircraft, to fire these weapons and a huge professional army to support the nuclear programme. Yet all that nuclear infrastructure did not stop the United States from breaching its air space, inserting soldiers in the ground right under the Pakistani militaryâ€™s nose, hunting down bin Laden and his associates in the house and flying away with his body. All without Islamabadâ€™s consent, according to the version put out by both sides. Things could have spun out of control, the Pakistani military could have engaged the Special Forces with unpredictable results. The air force according to reports did scramble its fighters, so there was always the chance of a fight. Yet as Colby says it is striking â€“ and a lesson for others â€“ that America seemed willing to take its chances against a nuclear-armed power. It shows that nuclear weapons do not provide blanket protection. â€œCountries that have nuclear weapons can still be confronted and operated against without escalation to nuclear use, particularly when the objective pursued is limited and discriminate, and especially when that objective is connected to a truly vital national interest,â€ he writes. In Pakistanâ€™s case, of course realistically speaking, there was no chance it would contemplate the use of nuclear weapons against the United States and that must have been factored into U.S.President Barack Obamaâ€™s calculus as he took the decision to proceed with the operation, Colby says. Nevertheless a message has been delivered to nuclear states and those trying to acquire weapons that they can be challenged.