What is the contrast between the Congress of Vienna and the Peace of Westphalia?

Answer 1

The 1648 Peace of Westphalia

was the result of negotiations between the major European powers

to end the Thirty Years War.However,not all of them were of the same mind when negotiations opened,and the process dragged on for some time - 1643 to 1648,and for complicated reasons met at a number of different locations.Minor powers also had a significant input (again,for complicated political reasons).Further,the Peace of Westphalia didn't end all hostilities,war between France and Spain continuing for another 11 years.
Another major factor about the process that led to the Peace of Westphalia was that France bossed most of what went on.

In contrast,The Congress of Vienna

met not to discuss any peace treaties, but to settle all outstanding political and territorial questions to the satisfaction of the Great Powers following the defeat of Napoleon,all of which were of the same mind,and all of which were prepared to reach an amicable agreement with each other.The original plan had been to exclude (or least sideline) the minor powers,but the extremely able Talleyrand turned up,uninvited,to represent France, and skilfully inserted himself into the whole decision making process by building a coalition with representatives of the minor powers who were present,ostensibly claiming to be there to give a voice to their views in the main council chamber.

Vienna took much less time than Westphalia (a mere 9 months compared to 5 years), despite being discombobulated by Napoleon's escape from Elba and the subsequent 'Hundred Days' and Waterloo campaign, and there were no ongoing wars or conflicts left unresolved by the Congress.

Another big difference was that after Vienna,there was no major general European war for nearly a century until WW1 broke out in 1914. After the Peace of Westphalia,Europe was at it again with the war of the League of Augsburg by 1688,which saw opposing coalitions of major and minor European powers ranged against each other,and several other such general European wars within less than a century.

The Congress of Vienna is often seen as,and criticized for,being a conservative European reaction, but there was a real willingness and attempt by all the major European powers to establish a settlement that would prevent the widespread wars between coalitions of powers that had plagued Europe for over 3 centuries,and in this were very successful - unlike the Peace of Westphalia.