British Prime Minister Tony Blair deserves great credit for his leadership in the war on terror, as well as his steadfast support for the United States in the dark days following the 9/11 attacks. He played a key role in the liberation of both Afghanistan and Iraq, and today over 12,000 British troops are fighting in these critical theaters of operation. The fact that tens of millions of Afghans and Iraqis no longer have to suffer the medieval savagery of the Taliban or the brutal boot of Saddam Hussein and his murderous Baathist thugs is due to the courage of American and British soldiers who have fought for their freedom.

Blair should be viewed as that rare politician who sacrificed popularity for principle in the global battle against terrorism. He towered above his close contemporaries on the international stage such as German Chancellor Gerhard Schröder and French President Jacques Chirac, who barely lifted a finger to help the United States, and for whom the transatlantic alliance was a museum piece of merely sentimental value.

His leadership in other key areas however was all too often weak and misguided, including British policy toward the European Union. Blair significantly failed to advance British interests in Europe during his time as Prime Minister, and oversaw the further erosion of British national sovereignty within the EU. Throughout his premiership, Blair was an unfailing supporter of further integration in Europe, backing both the European single currency as well as the original European Constitution. Fortunately, huge British public opposition convinced Blair to keep the pound, and the Constitution was rejected by both the French and Dutch electorates.

Instead of standing up to the EU, Blair was often steamrollered by it. He failed to face down French bullying over the Common Agricultural Policy (CAP), the world's biggest protectionist racket, which accounts for a massive 40% of the EU's 123 billion euro budget. French farmers receive about a quarter of EU agricultural subsidies, which amounted to a staggering 150 billion euros for France between 1994 and 2003. There is no sign that the CAP will disappear anytime soon, and over the past decade Blair barely made a dent in it. In the meantime, according to the British think tank Global Vision, Britain's net contributions to the EU budget are set to double to $12.8 billion by 2011. What Britain actually gets in return for this huge outlay is difficult to fathom, beyond more red tape and bureaucratic interference.

Under Blair's watch there were also major concessions on defence policy and legal sovereignty. In 1998, the Blair administration introduced the European Convention on Human Rights into British law through the Human Rights Act, seriously undermining Britain's long-term ability to combat domestic Islamic terrorism and extremism. In the same year, Blair signed the Saint-Malo declaration with France, which paved the way for British backing for a European Union army, operating if necessary outside of the NATO framework. London and Paris agreed that the EU "must have the capacity for autonomous action, backed by credible military forces, the means to decide to use them, and readiness to do so, in order to respond to international crises." The European Security and Defence Policy (ESDP) poses a fundamental threat not only to the future of the NATO alliance, but also the Anglo-American special relationship, which will ultimately be sidelined by it.

Next week Blair travels to his final EU summit in Brussels before handing over the reins of power to his Chancellor Gordon Brown on June 27. At the summit, Blair will face intense pressure from France and Germany to sign Britain up to a new European "treaty", in effect, a slightly revised European Constitution, only this time round there will be no need, according to Europe's ruling elites, for inconvenient national referendums that might derail it. When faced with popular, democratic opposition, Europe's solution is to typically go around it, and force change through the back door, without public consultation.

If Blair does commit Britain to this new treaty without promising a referendum on the issue, it would represent a huge betrayal of British interests as well as a massive slap in the face for the British public, who are overwhelmingly opposed to further political integration in Europe. To all intents and purposes, the proposed revived constitution is little more than a blueprint for a federal European superstate, with a European foreign minister, a charter of fundamental rights, and the imposition of European criminal law across the union through a system of qualified majority voting.

Blair must show some backbone by standing up to the proposed European treaty. He needs to demonstrate the same kind of political courage and leadership he so ably demonstrated in the aftermath of 9/11 and his decision to support the liberation of both Afghanistan and Iraq. Blair stood up to Paris and Berlin then, and he needs to do so now. He must insist that the British electorate be given the deciding say on whether the new constitution should be adopted and promise a public vote before there is any agreement. If he fails to do so, he will end up selling British sovereignty for the illusory dream of 'unity' in Europe, and ultimately damn his own place in history.

Dr. Gardiner is the director of the Margaret Thatcher Center for Freedom at the Heritage Foundation.