Because the EU gets a quarter of its oil from Russia, OilPrice analysed.
The EU, along with the U.S., unleashed a barrage of sanctions against Russia following its invasion of Ukraine.
While Russia's oil & gas industry has been an obvious target for sanctions, just as it was in Iran and Venezuela, so far, the only action taken was by the U.S. and the UK, which both announced bans on Russian oil imports - neither of which was to take effect immediately.
The EU has been the object of particularly intensive pressure from the Ukrainian government to target Russia's oil & gas and it has, based on public statements by various officials, made commitments to do that at some later date.
Even without an oil embargo, the Russian oil industry is already feeling the impact of the sanctions, according to various reports.
President Putin himself admitted that the sanctions have affected the normal operation of the industry, saying Russia needed to re-orient its oil flows from Europe to Asia.
Yet just how severe the blow has been - and how severe a blow a full oil embargo from the EU will be - remains unclear.
This week the Kremlin critic Mikhail Khodorkovsky, said:
- If Putin has to redirect oil & gas exports from the European to the Asian markets, he will lose over half of his revenue
It would also be surprising to expect the Russian authorities to admit the full extent of a potential blow from an oil embargo.
The key, however, is not in the absolute effect of such an embargo.
It is in the relative effect an oil embargo would have on the EU.
Before the 1st waves of sanctions hit it, more than half of Russia's oil exports were going to the EU.
Since then, the amount of Russian oil going to the EU has declined and, according to the IEA, will decline a lot further next month, reaching 3 million bpd because of well shut-ins.
European governments are already putting measures in place to help their populations cope with higher energy prices, including higher fuel prices.
Substantial discounts on gasoline and diesel prices have been implemented in France, Germany, Italy and Spain, for example.
The Netherlands, meanwhile, reduce the rate of its excise duty to alleviate the pain at the pump.
All this will seem like nothing if a full embargo comes into effect.
More importantly, the EU will need to find a replacement for those more than 3 million bpd in crude and fuels and find it fast.
It is already buying up U.S. oil, but it will need to step up these purchases significantly and quickly, which would be difficult to do, especially the latter part; there is no pipeline running under the Atlantic and this is precisely why the EU has not yet agreed on a full oil embargo on Russia.