Bird Dog, Britain is a part of the EU, but not a member of the Eurozone.
Much of the printed press here verges on the xenophobic with regards to Europe. If you look at the
Daily Mail,
Telegraph,
Times (paywall)
Sun,
Daily Express or
Daily Star then there's a very good chance at least one of them will be carrying a hostile story about the EU. A large part of the governing Conservative party shares these instincts.
Greece shouldn't have been a part of the Eurozone initially. The entry criteria were fudged to allow it to join, in part because historically it's the epicentre of European culture.
The issues are largely that tax evasion is a national pass time for the Greeks, there's an incredibly generous social welfare system, a very well paid civil service, and there hasn't been the political will to take on the vested interests who benefit from this, which is probably a large segment of the population.
Ireland and Spain were both in a good shape before the GFC, but they had housing market crashes that wrecked their economies, in particular their financial sector. Much of Ireland's debts stem from a government guarantee of the banking sector.
Italy has a large public sector debt, but the budget deficit is smaller than Germany's. The problems are partly due to markets getting nervous, and the size of the Italian economy being such that no-one could afford to bail it out. And partly because Berlusconi didn't show a huge amount of economic competence.
The technocratic government there being headed up by Mario Monti could well resolve matters. There's scope for public sector cuts, and the Italian state holds a significant number of assets that could be privatised to raise money to pay down debt.
The US probably gets a free pass because the chart was drawn up by an American.
The reason that the US and UK don't have the junk bond status of the PIIGS, despite being in a similar fiscal position, is that both countries can print or devalue their currencies to reduce pressure. So (arguably) by being able to mismanage their finances, they're in a better position, and that's why France was downgraded, but the UK remains AAA for now.