The Dow Jones Industrial Average (^DJI -0.33%) broke a four-day win streak today, as several troubling geopolitical developments sent investors rushing to the sidelines. A Malaysia Airlines flight from Amsterdam to Kuala Lumpur crashed in an eastern part of Ukraine, instantly raising suspicions that one of the parties in the Russia-Ukraine conflict was to blame. According to the Wall Street Journal, U.S. intelligence has confirmed that a surface-to-air missile was used to bring the plane down. The flight was carrying 295 people, and the perpetrators at the time of this writing are unknown.

Later in the day, the Israeli military launched a ground operation in Gaza, signaling increasing tensions in that part of the world, as well. The global turmoil was too much for Wall Street to handle, and by day's end, the Dow had lost 161 points, or 0.9%, to end at 16,976.

Ninety percent of blue chip stocks lost ground today, and McDonald's (MCD -0.84%) was one of the unlucky many, shedding 0.9%. While you've gotta give the company credit for exploring some quirky ways to boost revenue -- lovebirds in Hong Kong can now choose to tie the knot in 15 different locations -- the future of the business doesn't look as rosy as it once did. Franchisees, in particular, worry about the direction of their businesses: asked to rate their sales outlook for the next six months on a scale from one to five, franchisees gave a 1.84 average, the lowest figure since Janney Capital Markets started conducting the polls back in 2003.

American Airlines shares took a haircut today, although the company has nothing to do with the Ukrainian tragedy. Image Source: American Airlines.

Shares of each and every major airline that trades on a U.S. exchange fell today after the tragedy in Ukraine. American Airlines (AAL -1.16%) was no exception, losing 4.1% on Thursday. This secular sell-off strikes me as an unwise long-term move for investors who believe in the continued resurgence of the airline industry. That said, I can think of just two scenarios going forward that would justify today's sell-off. First, if travelers across the globe decide to stay closer to home and restrict travel, fearing a terrorist attack, American Airlines and its peers would suffer. Second, if this incident sparks extreme military escalation in the Ukraine-Russia conflict, oil prices would be prone to spike on the turmoil, sending the cost of jet fuel through the roof.

Thursday's chaotic stock market was easily navigated by shares of World Wrestling Entertainment (WWE), which added 6.1% today. The stock is still reeling from the absolute smackdown it received two months ago, when shares plunged 45% in a single day on news of a severely disappointing broadcasting deal with Comcast's NBCUniversal. The only major catalyst remaining for WWE this year is the success of the company's WWE Network, a monthly streaming service to which the company needs to lure 1.4 million subscribers in order to break even. Motley Fool colleague Wade Michels believes that number is within WWE's reach.