The Saudi role in this war has been to come up with the oil price shock – which is hurting not only Russia but also Iran and Venezuela, among others.

This is an attempt to limit the supply of Russian oil and gas to the EU, thus increasing the share of supply obtained by Saudi Arabia, Qatar and the other Gulf allies of the US. Also to increase the price of non Russian oil and gas.

When the Civil War in Ukraine failed to draw Putin directly into the war on the side of the rebels and the sanctions thus far applied against Russia failed to have any meaningful effects a different tactic was tried by the US and Saudi Arabia by dropping the oil price to below $50 to cause the Ruble to collapse and (they thought) to destabilize Russia's economy.

Both oil and Rubles have dropped by 50% so Russia is still getting the same number of Rubles for it's oil, but the number of Rubles Russia gets for it's natural gas sales has increased substantially because the price of gas hasn't dropped nearly as much as oil. (This is reflected in Russia's record government budget surplus of $23bn from January to November 2014.)

The major cause of concern for Russia are large capital outflows, but China has stepped into the breach by supporting the Ruble and by saying it will up it's levels of investments in Russia. China has $4tn of Foreign Currency Reserves.

This is a huge bonus for China who will be buying Rubles and Russian assets while they are undervalued. This is on top of the bonus to China of the 50% drop in the oil price (China is the largest importer of oil after the US).

N.B. the devaluation of the Ruble is causing high price inflation in Russia from the increased costs of imports. This will encourage Russia to produce more itself and to import less from abroad, increasing Russia's already substantial trade surplus.

The BRICS increasingly successful actions have marginalized the US Dollar in international trade and will put an end to the Petrodollar system and the Dollar as Reserve Currency.

The US created ISIS in the hopes that they would be able to remove Assad so that Saudi Arabia and Qatar could build a pipeline through Iraq, Syria and Turkey to supply Europe with gas that is currently being supplied by Russia. When this plan failed a false-flag chemical attack was blamed on Assad in the hopes of justifying a complete invasion. So far that full scale invasion is being blocked by the Russians.

Sources:

Goldman Sachs On The Myths & Realities Of Russia's Oil Sector
http://www.zerohedge.com/news/2015-01-26/goldman-myths-realities-russias-oil-sector

Financial Times Lex: Russia is a Creditor to the World - Default Risk Non-existent
http://russia-insider.com/en/2014/12/22/2104

China's medium term plans are to replace the US Dollar as Reserve Currency by forming a coalition with the BRICS
http://ian56.blogspot.com/2014/12/chinas-medium-term-plans-are-to-replace.html

References:

1. Washington's New Iron Curtain to drive a wedge between Russia and the EU to the detriment of both and the high level meeting in Yalta in September 2013 that discussed Ukraine's future

It Was All Planned at Yalta

In September 2013, one of Ukraine’s richest oligarchs, Viktor Pinchuk, paid for an elite strategic conference on Ukraine’s future that was held in the same Palace in Yalta, Crimea, where Roosevelt, Stalin and Churchill met to decide the future of Europe in 1945. The Economist, one of the elite media reporting on what it called a “display of fierce diplomacy”, stated that: “The future of Ukraine, a country of 48m people, and of Europe was being decided in real time.” The participants included Bill and Hillary Clinton, former CIA head General David Petraeus, former U.S. Treasury secretary Lawrence Summers, former World Bank head Robert Zoellick, Swedish foreign minister Carl Bildt, Shimon Peres, Tony Blair, Gerhard Schröder, Dominique Strauss-Kahn, Mario Monti, Lithuanian president Dalia Grybauskaite, and Poland’s influential foreign minister Radek Sikorski. Both President Viktor Yanukovych, deposed five months later, and his recently elected successor Petro Poroshenko were present. Former U.S. energy secretary Bill Richardson was there to talk about the shale-gas revolution which the United States hopes to use to weaken Russia by substituting fracking for Russia’s natural gas reserves. The center of discussion was the “Deep and Comprehensive Free Trade Agreement” (DCFTA) between Ukraine and the European Union, and the prospect of Ukraine’s integration with the West. The general tone was euphoria over the prospect of breaking Ukraine’s ties with Russia in favor of the West.
Read more at:- http://www.a-w-i-p.com/index.php/2014/06/09/washington-s-iron-curtain

Previous Related articles
Why Obama visited Riyadh to pay tribute to the largest funders of Islamic Extremist Terrorism in the world
http://ian56.blogspot.com/2015/01/the-leaders-of-west-went-to-pay-tribute.html

Further Reading
Russian Sanctions Might Be Obama’s Greatest Blunder - pushing Russia and China closer together faster

The $700bn+ (over ten years) deal to supply China with more energy, together with the required pipeline expansions

The Russian supply of advanced weapons to China (previously only older technology was supplied)

The replacement of Exxon with Chinese and Asian partners to develop Russia's newly discovered Arctic and other oil fields

The use of China's $4tn Foreign Currency Reserves to bolster the Ruble and invest in Russia
and more
See:- http://oilprice.com/Energy/Crude-Oil/Russian-Sanctions-Might-Be-Obamas-Greatest-Blunder.html