Turkey's decision to shoot down a Russian warplane was a provocative and portentous act.
That Sukhoi Su-24, which the Turks say intruded into their air space, crashed and burned — in Syria. One of the Russian pilots was executed while parachuting to safety. A Russian rescue helicopter was destroyed by rebels using a U.S. TOW missile. A Russian marine was killed.
"A stab in the back by the accomplices of terrorists," said Vladimir Putin of the first downing of a Russian warplane by a NATO nation in half a century. Putin has a point, as the Russians are bombing rebels in northwest Syria, some of which are linked to al-Qaida.
As it is impossible to believe Turkish F-16 pilots would fire missiles at a Russian plane without authorization from President Tayyip Recep Erdogan, we must ask: Why did the Turkish autocrat do it?
Why is he risking a clash with Russia?
Answer: Erdogan is probably less outraged by intrusions into his air space than by Putin's success in securing the Syrian regime of Bashar al-Assad, whom Erdogan detests, and by relentless Russian air strikes on Turkmen rebels seeking to overthrow Assad.
Imperiled strategic goals and ethnicity may explain Erdogan. But what does the Turkish president see down at the end of this road?
And what about us? Was the U.S. government aware Turkey might attack Russian planes? Did we give Erdogan a green light to shoot them down?
These are not insignificant questions.
For Turkey is a NATO ally. And if Russia strikes back, there is a possibility Ankara will invoke Article V of NATO and demand that we come in on their side in any fight with Russia.
And Putin was not at all cowed. Twenty-four hours after that plane went down, his planes, ships and artillery were firing on those same Turkmen rebels and their jihadist allies.
Politically, the Turkish attack on the Sukhoi Su-24 has probably aborted plans to have Russia join France and the U.S. in targeting ISIS, a diplomatic reversal of the first order.
Indeed, it now seems clear that in Syria's civil war, Turkey is on the rebel-jihadist side, with Russia, Iran and Hezbollah on the side of the Syrian regime.
But whose side are we on?
As for what strategy and solution President Obama offers, and how exactly he plans to achieve it, it remains an enigma.
Nor is this the end of the alarming news.
According to The Times of Israel, Damascus reports that, on Monday, Israel launched four strikes, killing five Syrian soldiers and eight Hezbollah fighters, and wounding others.
Should Assad or Hezbollah retaliate, this could bring Israel more openly into the Syrian civil war. And if Israel is attacked, the pressure on Washington to join her in attacking the Syrian regime and Hezbollah would become intense.
Yet, should we accede to that pressure, it could bring us into direct conflict with Russia, which is now the fighting ally of the Assad regime.
Something U.S. presidents conscientiously avoided through 45 years of Cold War — a military clash with Moscow — could become a real possibility. Does the White House see what is unfolding here?
Elsewhere, yet another Russia-NATO clash may be brewing.
In southern Ukraine, pylons supporting the power lines that deliver electricity to Crimea have been sabotaged, blown up, reportedly by nationalists, shutting off much of the electric power to the peninsula.
Repair crews have been prevented from fixing the pylons by Crimean Tatars, angry at the treatment of their kinfolk in Crimea.
In solidarity with the Tatars, Kiev has declared that trucks carrying goods to Crimea will not be allowed to cross the border.
A state of emergency has been declared in Crimea.
Russia is retaliating, saying it will not buy produce from Ukraine, and may start cutting off gas and coal as winter begins to set in.
Ukraine is as dependent upon Russia for fossil fuels as Crimea is upon Ukraine for electricity. Crimea receives 85 percent of its water and 80 percent of its electricity from Ukraine.
Moreover, Moscow's hopes for a lifting of U.S. and EU sanctions, imposed after the annexation of Crimea, appear to be fading.
Are these events coordinated? Has the U.S. government given a go-ahead to Erdogan to shoot down Russian planes? Has Obama authorized a Ukrainian economic quarantine of Crimea?
For Vladimir Putin is not without options. The Russian Army and pro-Russian rebels in southeast Ukraine could occupy Mariupol on the Black Sea and establish a land bridge to Crimea in two weeks.
In Syria, the Russians, with 4,000 troops, could escalate far more rapidly than either us or our French allies.
As of today, Putin supports U.S.-French attacks on ISIS. But if we follow the Turks and begin aiding the rebels who are attacking the Syrian army, we could find ourselves eyeball to eyeball in a confrontation with Russia, where our NATO allies will be nowhere to be found.
Has anyone thought this through?
Patrick Buchanan has been an adviser to three presidents, a two-time candidate for the Republican presidential nomination, and the nominee for the Reform Party in 2000. He was also a founding member of "The McLaughlin Group," which began on NBC, and CNN's "Capital Gang" and "Crossfire." His latest book is: "The Greatest Comeback: How Richard Nixon Rose From Defeat to Create the New Majority." For more of his reports, Go Here Now.