The Russian market contributes a significant percentage to the world's economy. Being one of the largest oil producers, their market can affect virtually all prices both in stock market and in Forex market not to mention the prices of commodities that rely on crude oil. As such, rather than downplaying their influence experts should try as much as possible to come up with ways to help in resolving issues that affect that particular market.
America as a country has always wanted to remain in the top spot for power since the beginning. There have been many countries that want the authority to be in charge. Russia is no different now. Many countries have a high influence on imports, exports, and the production of goods that aren't America. Especially with Russia being in the news lately for not-so-positive things, of course any influence would be talked down.
I do not believe that experts are downplaying the influence of RUssian markets on the U.S. If anything, I would have to say that the situation is reversed, and Russian markets are being influenced by the Unites States and its culture, trends, style of dress, and other very important factors.
Russia may be influential when it comes to trade and imports for America. However, the United States does not agree with nor align with many of Russia's policies. Russia makes decisions based on force and fear. The U.S., is still considered a democratic nation. Leading by force is not an option for this nation. So, whereas, Russia appears to talk a big game and have great motives, they are not influential enough on the United States.