Russian officials caution that U.S. direct military support for Israel risks triggering wider instability across the Middle East.

Russia is telling the United States not to strike Iran because it would radically destabilise the Middle East, Russian Deputy Foreign Minister Sergei Ryabkov said on Wednesday, and Moscow said Israeli strikes risked triggering a nuclear catastrophe.

Iran warned that if the United States joins Israel's conflict with Iran, it will result in an "all-out war" in the Middle East region.

As yet another one of his key allies in the region faces an existential crisis, Vladimir Putin is presented with a major opportunity — and many challenges.