Although we don't believe in timing the market or panicking over daily movements, we do like to keep an eye on market changes -- just in case they're material to our investing thesis.

Rising fears that the U.S. will intervene in the Syrian conflict has oil prices up and the U.S. markets down. As of 1:25 p.m. EDT the Dow Jones Industrial Average (DJINDICES:^DJI) has dropped 136 points, or 0.91%, to 14,811. The S&P 500 (SNPINDEX:^GSPC) is down 1.29% to 1,635.

There were two U.S. economic releases today.





Case-Shiller 20-City Composite Home Price Index




Case-Shiller U.S. National home Price Index




Consumer Board Consumer Confidence Index




Both can basically be overlooked. The Case-Shiller home price index continued to rise in June at a slightly slower pace than in May. Year over year, the index is up 12.1% -- no change there since May. The big question is what July's numbers will hold. Last Friday we found out that new-home sales dropped a seasonally adjusted 13% in July. Tomorrow we get the pending-home-sales report for July, which should show whether pending home sales also dropped sharply. Housing has led the U.S. recovery, but many believe the housing market will be challenged by the large jump in mortgage rates. We will have to wait until tomorrow to find out more.

Meanwhile, the Conference Board's index of consumer confidence rose to 81.5, beating both July's result and analyst expectations of a drop to 78. While confidence is slowly returning, the index is well below the normal level for a growing economy.

These reports have not been enough to push the Dow upward. All but one of the Dow's 30 stocks are in the red. Fears are rising of a U.S. military intervention in Syria after reports indicated that Syrian government troops used chemical weapons in an attack against rebel forces just outside of Damascus. Syrian President Bashar al-Assad denied the reports in an interview with Russian newspaper Izvestia yesterday. President Obama had previously said that a chemical-weapons attack would be a red line that, if crossed, would lead to a U.S. intervention, specifically saying in an interview with NBC a year ago: "We have been very clear to the Assad regime, but also to other players on the ground, that a red line for us is we start seeing a whole bunch of chemical weapons moving around or being utilized. ... That would change my equation."

The fear of U.S. military intervention and possible spillover effects in the region have the price of oil, as well as traditional safe heavens like gold and U.S. Treasuries, on the rise. Both Brent crude and WTI crude are up roughly 3%, while gold is up 1.8% to $1,418. While uncertainty is rising, what can investors do? Your time is best spent ignoring the market's ups and downs and focusing on your investing plan -- or making an investing plan, if you don't have one. If the market's drop continues, opportunities will arise for long-term investors to pick up undervalued companies.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.