With the most striking rhetorical flourish of his young presidency, George W. Bush has set in motion nothing short of an open-ended war on terrorism. In his historic address to a rapturous Congress on Thursday, Mr Bush appeared to sense the time had come for action after days of words - as well as the need to cloak his rule in the healing of America's deep wounds following the attacks on Washington and New York. Yet what he has promised threatens to upset America's diplomatic and military assumptions, creating historic challenges to be solved long after Thursday's ringing applause has died. If he lives up to his promises, America's foreign and military policy may never quite be the same. Mr Bush left little doubt that he had prepared for a war with Afghanistan, a country whose mujahedeen fighters ensnared the Soviet Union in the 1980s. He called upon its Taleban leadership to 'act immediately' to hand over Osama bin Laden and the leaders of his al-Qaeda network. He detailed the brutality of its regime. 'They will hand over the terrorists or they will share in their fate,' he said. But he went further, much further, as he tried to answer questions that 'Americans are asking'. He made clear the rounding up of al-Qaeda was just the beginning. He couched the fight against terrorism in terms of the 'murderous ideologies' of the 20th century - listing fascism, Nazism and totalitarianism. And he promised his massive battle would be on military, legal, diplomatic and financial fronts, involving the support of many countries. Countries now had to decide whether to join the task or risk being declared 'hostile nations' - a term with sweeping diplomatic and military consequences. He made abundantly clear that in other dealings, foreign states may be viewed through the prism of support for the ongoing battle. 'Either you are with us, or you are with the terrorists,' he said. 'How will we fight and win this war? We will direct every resource at our command - every means of diplomacy, every tool of intelligence, every instrument of law enforcement, every financial influence, every necessary weapon of war - to the disruption and to the defeat of the global terror network.' He spoke of difficulties and dangers ahead, making clear in no uncertain terms that he wanted the military 'ready'. There were fears, however, that he may have over-stretched the rhetoric as he neared the speech's climax. 'The course of this conflict is not known, yet its outcome is certain,' he said. On this point, many may disagree. At what point will victory be declared over the threat of terrorism? When will America's cities feel they can indulge in ticker-tape parades to honour their military heroes? Will it not be seen as a failure every time a new terrorist act is carried out? How will the public feel about dying soldiers in the long term? It is war without borders, a defined enemy or a finite conclusion. Hours before the speech, his own Defence Secretary, Donald Rumsfeld, could not coherently define victory in such a conflict. In this regard, Mr Bush finds himself in unchartered waters, far removed from conventional military or foreign policy doctrine. Already his administration seems unsure whether to pull Saddam Hussein's Iraq into the early stages. Thumb a few recent foreign policy tomes and analyses and there is virtually nothing to guide him. The sort of enemy he faces has been defined only in the most conceptual terms by strategic thinkers, part of an 'asymmetrical threat' that worries the likes of Mr Rumsfeld. Among those smiling and clapping in support was his charismatic Secretary of State, Colin Powell. Mr Powell, chairman of the Joint Chiefs of Staff during the Gulf War, has defined himself by the 'reluctant warrior' image. A Vietnam veteran, he has written extensively about the need to ensure future engagements have finite objectives with firm goals when it comes to committing America's vast military to action. As much as anyone in the Bush cabinet, he seems aware of the social, political and military swamp that developed out of the ill-conceived Vietnam adventure. After 11 years it brought defeat. Mr Powell finds himself in another mission with no clear end. Flanked by a Congress representing a nation now rallying around him like other wartime presidents, Mr Bush looked as relaxed and comfortable as he had ever in front of a microphone. He seemed aware of the challenges but was in no mood to detail quite how they would be overcome. This was, after all, a 'new and sudden' threat and the rest would come later. Rhetoric - some of the most dramatic uttered in Washington in recent years - was his safe harbour on Thursday. 'I will not forget this wound to our country or those who inflicted it,' he said. 'I will not yield; I will not rest; I will not relent in waging this struggle for freedom and security for the American people.' Nothing short of his own presidency and the stature of his nation will depend on it.