The Russian oil price cap that went into effect Monday could, over time, be an important Western counterweight to OPEC in determining world oil prices.

Driving the news: After months of wrangling, the mechanism to try to cap prices of Russian crude oil shipped by sea went into effect on Monday.

• Parties to the deal include the G7, the European Union and Australia, all of whom agreed that the highest price they'd pay for Russian oil would be $60 a barrel.
• For its part, Russia has rejected the idea of the price cap, though in practice its pariah status means it's selling oil on the global market for less than $60 a barrel, analysts say.

The price cap is designed to limit windfall profits Russia might reap from energy prices that have surged because of its invasion of Ukraine.

• But it's also supposed to provide incentives for Russia to keep producing the oil which the world economy still needs. India and China are now buying most Russian crude.

The big picture: No one knows how effective the new price-capping plan will be at achieving those goals.

• But the birth of a buyers club formed by the world's richest nations to coordinate their purchasing decisions in pursuit of specific prices still amounts to a major moment for world oil markets.
• While Russia is its current focus, such a group could perhaps be a plausible counterweight to OPEC, the cartel of oil-producing countries that has tried to maximize revenues for its members since it was established in 1960.

What they're saying: "If you're OPEC, you're looking at this and you're saying, 'Wait. You know, I'm not sure this Russian-focused tool couldn't be used against us,'" Kevin Book, an analyst at energy research firm ClearView Energy Partners tells Axios.

• Similarly, analysts from Rystad Energy noted on Monday that "the general view among OPEC countries is that the price cap idea sets a bad precedent and could be implemented against that group in the future."

Yes, but: U.S. policymakers are keen to stress that the current price-cap coalition is focused only on Russia, rather than the broader oil markets.

• "This is not a buyers cartel. This is a sanctions regime directed at Russia," said Ben Harris, a Treasury department official, while speaking at Harvard University on Monday, adding, "This is not about a global buyers cartel for all oil. This is about oil that is coming out of Russian soil and nothing else."

What we're watching: How rising tensions between OPEC and the West could play into the oil cartel's closely watched decisions on output in the coming months. (After holding a virtual meeting Sunday, OPEC and its allies, including Russia, voted to stick with its previously agreed-upon production targets.)

• Oil-producing nations such as Saudi Arabia are trying to simultaneously manage longstanding defense relationships with the U.S. (where officials want an increase in output), growing linkages to authoritarian countries like Russia and China — and an uncertain outlook for crude oil demand due to China's unsteady economy.