Iran's fateful decision to send a military drone from Syria into Israeli airspace last weekend has changed everything in the Middle East.
Israel responded fiercely with a massive airstrike that took out as much as half of Syria's air defenses.
The U.S. in turn issued a strong statement of support for Israel.
Now, it's Russian President Vladimir Putin's move. He has to decide whether to keep backing Syria and Iran or decrease his risks in the region.
Putin has some critical questions he needs to answer to make his decision easier.
Is supporting Bashar al-Assad still worth it?
Russia has been supporting Syrian President Bashar al-Assad with air forces and troops in that country's civil war since 2015. 17 months later, Assad's forces have regained the upper hand in the civil war and ISIS has been basically defeated in that country.
But even before this latest Iranian provocation, the Russian death toll was starting to creep up. Bloomberg is reporting that as many as 200 Russian contract soldiers fighting for the Syrian army were killed last week in an attack on a base held by U.S. and Kurdish forces in the Deir Ezzor region. About 400 of those Russian paramilitary troops have now been killed in the war. The number of official Russian soldiers killed in Syria is an additional 40 or so.
Russian soldiers dying in battle so far from home can erode support even for the most powerful dictator. The Soviet regime was thought to be invulnerable to internal opposition, but the long and costly Afghanistan war helped to prove that wrong.
Is backing Iran really worth it?
Propping up Assad isn't really so much about helping Assad. The Syrian government has been a major ally and quasi-proxy for Iran for years, long before the civil war began. So Russia's decision to help Assad is more about supporting Iran.
But with Israel jumping into the fray, backing Iran now comes with a lot more baggage. Israel and Russia have basically stayed out of each other's way in Syria, but that is going to be harder to do going forward. Israel has made it clear to Putin that another clash with Iranian forces in Syria is inevitable.
In other words, Russia has been able to thread the difficult needle that allowed it to back Syria and indirectly aid Iran for two years plus without making an outright enemy of Israel. Those days look like they're soon going to be over.
How can Russia best accomplish its goals in the Middle East?
Russia has been following only one rule pertaining to its involvement in the Middle East since at least 2013: Get involved everywhere.
While Putin continues to back many Iranian interests, the Kremlin is also making infrastructure and oil supply deals with Iran's archrivals in Saudi Arabia. Libya and Egypt are also areas where Putin has been increasing Russian military influence. The standard operating procedure for Russia in the Middle East seems to be to make deals with everyone first and ask questions later.
But there's an old Yiddish saying that, "you can't dance at all weddings," and Iran's provocation of Israel is starting to make that more of a reality for the Kremlin.
It's time to choose a side.
At long last, Putin needs to pick a side. The cost in human lives alone must make him see that by now. The risks in Russia's Syrian and overall Middle Eastern adventurism are mounting on the Iranian side of Putin's ledger. The other side of the ledger has much more to offer. Saudi Arabia has almost twice the GDP of Iran. Israel has the region's most powerful military. Thanks to the growing Saudi-Israeli alliance, Russia can easily work with both of them without conflict.
That's really what Putin's choice boils down to now. After this past weekend, that choice really isn't that hard at all.
Commentary by Jake Novak, CNBC.com senior columnist. Follow him on Twitter @jakejakeny.
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