And what exactly does being an ally of the US get us? Nothing except hate from those who hate America? Do we get aid? No: we paid off all debt incurred in WW2 ourselves. Are we even helped in the wars we join? No: our troops have to buy their ammo at premium prices from Americans in Afghanistan, because they don't get enough of their own.
You're forgetting Marshall Aid and 44 years of saving your rears from the Soviets. And even now, if the UK were to be threatened with invasion, China isn't helping.
Blair's legacy will unfortunately be a disastrous war. I say "unfortunately" because, in the sphere of foreign policy, his influence in the Balkans has mostly been positive (he largely inherited the NI resolution from Major). Domestically, he has redefined Labour around moderately progressive policies such as the minimum wage and healthcare spending - policies which the middle class could support and which therefore had an actual chance of passing. This isn't the Attlee era, and Royale's fate and the near-desintegration of the French socialists are a good example of what could have happened to Labour without Blair. In short, Blair gave Britain an actual second party, as opposed to one perhaps more consistent in its beliefs but unelectable. To that extent, he has strengthened British democracy, and I think that should be considered his real legacy, just as LBJ's real legacy was not Vietnam but the creation of a welfare state.