The German Constitutional Court approved that country's participation in a rescue fund and budgetary pact for the eurozone on Wednesday, helping assuage concerns in and out of the beleaguered monetary union.

While the court added the stipulation that legislative approval would be required for German aid over 190 billion euros, the decision breathes fire into German Chancellor Angela Merkel's plan to tame the mounting debt crisis that has plagued Europe for years. With this ruling, the creation of the European Stability Mechanism – which will control bailout funding and work with the European Central Bank to purchase national bonds -- will move forward.

Stocks rose in early trading on the news, with the Dow Jones Industrial Average (INDEX: ^DJI) up 0.3% and the S&P 500 (INDEX: ^GSPC) up nearly 0.4%. The euro gained half a percent against the U.S. dollar, rising to its highest level since May. European equity markets were also boosted by the ruling; the countries suffering the worst debt troubles were benefiting the most.

An opposite ruling could have placed the ECB's announcement last week to purchase debt of the Continent's economically troubled nations in jeopardy. Without Germany's assistance, any program to rescue struggling European economies and keep the region's common currency alive would have faced dire odds.