A decade ago, the world rightly stood in solidarity with the United States in the face of the 9/11 terrorist attacks.  The story of how the Bush Administration squandered that solidarity through Guantanamo, torture and the invasion Iraq is well known. Less well known is how the United Nations also lost its opportunity to unite world in principled counter-terrorism.

The 9/11 attacks provided the U.N. with an unparalleled opportunity to forge international agreement on a definition of terrorism. Whatever previous disagreements there were about freedom fighting and state terrorism, it was clear that the 9/11 attacks constituted terrorism. The killing of innocent people not engaged in hostilities in an armed conflict was terrorism; it did not matter whether they were in the planes, the World Trade Centre or the Pentagon.

On September 28, 2001, the Security Council demanded that all states enact tough counter-terrorism measures under its mandatory powers to enforce international peace and security. The Security Council offered no guidance on the definition of terrorism. It failed to so, even though a 1999 Convention on the Suppression of Terrorism Financing previously included a restrained but principled definition:  the intentional killing or injuring of those not engaged in armed conflict in order to intimidate a population or compel governments to act.

The Security Council's failure to encourage a definition of terrorism left states free to create their own definitions. Some defined terrorism very broadly so it could cover non-violent civil disobedience or even peaceful dissent; others selectively defined terrorism so that it would not include attacks on the civilians of an occupying power. A few countries, like Syria, managed both feats. Following an Arab Convention, it defined terrorism in an overbroad manner that included dissent while excluding "freedom fighting," so long as it was not directed at an Arab state.

Given its eagerness to promote counter-terrorism, the Security Council through its new Counter-Terrorism Committee essentially ignored human rights for three years after 9/11. This provided many countries with plenty of time to enact broad new laws. The Security Council now claims it recognizes that respect for human rights is part of a sustainable security strategy, but the stains of the first few years after 9/11 have lingered.

The Security Council's initial approach not only neglected human rights, but made strategic errors in counter-terrorism strategy. Responding to bin Laden's exaggerated reputation as a financier of terrorism and its desire to promote the 1999 Financing Convention, the Security Council focused on terrorism financing. Many countries made it a priority to enact terrorism financing and money laundering laws despite the small amounts required to finance deadly terrorism. One such country was Indonesia, which enacted a terrorism financing/money laundering law in 2002 when it should have been reforming its criminal law and policing to better deal with terrorism such as  the 2003 Bali bombings that killed 202.   The 9/11 commission  concluded that stronger terrorism financing laws could not have stopped what was most likely the most expensive act of terrorism in history, but the UN continues to make such laws a policy priority.

The Security Council also encouraged states to focus on refugee applicants as potential terrorists, thus encouraging them to use immigration law as a shortcut anti-terrorism law. This allowed democracies to rely on secret evidence against non-citizens even as the threat of home grown terrorism grew.

Finally, the Council followed Prime Minister Blair's lead after the 2005 London bombings in focusing on extremist speech. This approach was potentially divisive and downplayed the differences between extremist beliefs and acting on such beliefs in a violent manner.

It is one thing when one country, even one as powerful as the United States, makes strategic mistakes in counter-terrorism, but it is quite another when the UN makes mistakes in its global security legislation. The U.N. has learned from some of its mistakes. The Security Council now claims to play more attention to human rights and an Ombudsperson is available for those who may be wrongly blacklisted as terrorists. The General Assembly in 2006 developed a balanced counter-terrorism strategy, but unfortunately continued to fail to agree on a definition of terrorism.

Although nothing  could mitigate the evil and tragedy of 9/11, the failed and flawed counter-terrorism pursued by both the US and the UN in the years after that tragedy has squandered what little good could have come from that terrible day.

Prof. Roach is the author of The 9/11 Effect: Comparative Counter-Terrorism, published this month by Cambridge University Press.