Before I get to that, let me dispense with Spain & Italy (which you didn't mention). It's difficult not to objectively regard Spain's current foreign policy stance as an aberration, attributable to nothing more than Aznar's leadership. His pro-American position regarding Iraq is starkly unpopular in Europe and his party is now trailing the opposition Socialists for the first time since the last election. Spain has elections coming up in March, 2004. Even assuming Aznar's party manages to hold on - a dubious proposition at the moment - his successor (Aznar says he will not stand for office again) is very likely to realign himself firmly with France & Germany.
Italy, even more so than Spain, has traditionally been a strong partner in the Franco-German vision for a united Europe. Much like the Spanish situation, the current Italian stance has been almost entirely a product of Berlusconi's personal inclinations, and even at that a weak distancing. In other affairs, Berlusconi has been working as closely as ever with Chirac and Schröder toward advancing their vision of Europe; he has also stated recently that the U.S. must secure a second UN resolution authorizing war in Iraq. Much like a couple other states usually close to the Franco-German core, Italy's actions seem more driven by difficulty coming to terms with the transatlantic rift, rather than any genuinely resilient realignment away from France & Germany.
So, back to Britain. For a variety of reasons - fully acknowledged by Tony Blair, I might add - Britain cannot afford to remain forever outside the eurozone. The details are rather lengthy and in themselves peripheral to this topic (if nothing else, then let's just say that's my view of things). Britain will be compelled to make a choice, sooner or later, between staying right outside the EU door or fully integrating within the eurozone. Indeed, that's Blair's uppermost priority once this Iraq situation has been resolved, which he by every account intends to focus the remainder of his administration upon.
Now, if you say that the Security Council will be consigned to history, the next step is to look at where, precisely, states will then seek international stature. In particular, when making a relative assessment such as that between France and Britain (both declining powers in the grand scheme) then clearly the most immediate forum is the European Union. First of all, France has both a larger absolute economy and a greater population than Britain (many have lately lost sight of the fact that France is the 4th largest economy in the world). When combining France and Germany (the 3rd largest economy) the British economy isn't even in the ballpark, either by population or economic leverage.
Otherwise, one must consider the immediate aftermath of a resolution to the Iraqi situation; the impact on Blair's political viability. More likely than not, a successful campaign will invigorate his political capital, which he'll turn right around and invest into ushering Britain into the eurozone. On the off-chance that his position is crippled, then there's every likelihood that his Labor successor will prove far more favorable to the EU, not less so. Finally, a long-range enhancement of the EU at the expense of the UN in the geopolitical order most elevates the stature of Germany, over the long-run.
In short, by losing its position at the UN, Britain loses one of the two primary pillars of its international standing. The other is its "special relationship" with the U.S., but it's important not to overemphasize the long-range significance of that. First of all, as already stated, a Labor successor to Blair is likely to prove closer to the Continent and far more distant from America than has Blair. Secondly, one way or another, the current relative emphasis on military affairs will get resolved (for better or worse) at which point attention will swing rapidly back to economic orderings. Third, its important, as I already alluded toward, not to overlook the impact of a Germany unleashed from NATO & the EU.
But, that's a discussion for another thread, so I'll stop here (I think I'm beginning to ramble somewhat.. ;)
This should read:
[Aznar's] pro-American position regarding Iraq is starkly unpopular in Europe amongst Spaniards and his party is now trailing the opposition Socialists for the first time since the last election.
*sigh* I should've previewed those remarks. This should read: its important, as I already alluded toward, not to overlook the impact of a Germany unleashed from NATO within the EU.
I was about to get into a discussion of how Germany's not inconsiderable military budget is currently submerged into NATO as well as how its profile would be enhance by the elevation of the EDF, within Europe, versus the current primacy of both NATO & the UN (in their respective spheres). That's when I stopped myself, since that's an involved topic in and of itself...