Another day, another panic in Europe. The FTSE 100 (INDEX: ^FTSE) fell 1.97%, which naturally led to the Dow Jones (INDEX: ^DJI) opening off. As of 3:30 PM EDT, the Dow is sitting down 0.85% after regaining some ground throughout the morning.

The culprit once again is Greece, the country that has been holding the euro hostage for the past couple of years. In this edition of "As the Greece Burns," the country is once again in an austerity stalemate as far-left party Syriza -- which just won second place in the country's elections -- refused to join a coalition that was negotiating on talks to keep the EU-funded bailout of the country going.

Investors may be tired of Greece and all the drama surrounding it, and might even be tempted to ignore news surrounding the country. On its own, that could prove a good bet. Greece has a GDP of roughly $300 billion, which isn't a fantastic sum; China's economy "creates" a new Greece roughly every four months! Isolated solely on Greece, there are bigger drivers of the global economy for investors to be worried about. However, the country's continuing struggles do portend broader troubles that could affect the entire eurozone.

Greece isn't alone in sweeping government change, as there has been continuing backlash against austerity and governments supporting it. Among more stable countries, in France, Nicolas Sarkozy was deposed by Francois Hollande, while the ruling coalition in the Netherlands was brought down amid talk of budget cuts. Greece's political situation could be a future playbook for political backlashes in countries like Spain and Italy that could be the next to battle with austerity. Fellow Fool Sean Williams made a strong case for Spain being on an inexorable path to default. If his thesis proves correct, Greece is just the canary in the coal mine, and seeing how it handles either a euro departure or begrudgingly accepts reforms could prove telling to the future of the euro crisis.

For investors, the concern is that slackening Europe demand amid continuing instability across the eurozone could lead to hard-fought gains in earnings circling the drain. About 46% of S&P 500 (INDEX: ^GSPC) sales and a majority of growth comes from foreign markets. While China and other emerging markets provide powerful growth boosters, Europe is still the largest international market for most American companies. Whether banking exposure across big banks like JPMorgan (NYSE: JPM) or a beloved consumer brand like McDonald's, Europe's continuing struggles have an outsize impact on almost every Dow stock. For example, Pfizer (NYSE: PFE) gets 24% of its sales from developed Europe.

Long story short, Europe has problems. Then again, stare long enough at just about any economy today and you'll see a host of problems. In spite of all this, the recovery has continued since bottoming out in 2009. With some big road bumps ahead, investors should be aware of where their companies are generating sales, and how slowdowns in different regions can affect their investments. While that concern might not have been a huge issue for investors 25 years ago, it should be at the forefront of your mind when checking any new investment today.

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