The news that the leaders of the two parties in the US Congress have  finally reached a deal on raising the borrowing limit for the Federal Government will be a relief to many.
It was beginning to look as if the political divisions in the country had become so deep that the US political system itself had become paralysed.   If that were to happen, the entire world would suffer.
Party discipline is very weak in the US for a number of reasons. 
Each member of Congress must raise huge sums for his/her personal campaigns. So members pay as much attention to potential donors as they do to their national party. Political action committees, tied to particular causes,  that  raise funds for candidates  can have as much influence on  how House members  vote as their  national party has.
District boundaries are manipulated to create safe seats for one party or the other.  This means that the contest in the primary for the  party nomination is often more important that the General Election. So members tend to spend a lot of effort courting the extremes of their own party rather than middle ground voters
Because party “headquarters” thus has little or no influence over who is selected as a party candidate for the House ,the penalty to a House member for voting against the national interest is low, while that of voting against the interests of his/her constituents or big donors is very high indeed. 
Party discipline was not always as weak as it now is, but” reforms” introduced in the 1970s have made the system more “democratic”, but less manageable.
Part of the compromise agreed between Democrats and Republicans will mean automatic cuts in Defence and healthcare for the elderly if Congress is unable to agree on alternative cuts.
In the medium term, this means that US military capacity will reduce, and will be more focussed on America’s own immediate interests.
Europe will have take more responsibility  for its own defence, and work out what  threats it wants  to equip itself to deal with on its own, and what threats it will  simply have to ignore. Adventures, like the bombing of Libya, will require a bit more thought. The defence provisions of the EU Treaties may acquire a higher profile, and NATO may become less important.
The cuts in healthcare entitlements hopefully force reductions in the costs of health services, which are much greater in the US than they are in Europe.  Vested interests in medicine and law have driven American health costs up to a completely unsustainable level.
But by coming so close to the brink of default, Congress has created uncertainty about the reliability of US securities. This may lead to higher interest rates in the United States.  That could have a knock on effect on borrowers in Europe because the interest rates on US  Federal bonds set the floor for interest rates.