Russian warplanes entered Turkish airspace from Syria twice over the weekend, sending Turkish F-16s scrambling. In separate incidents on Monday, a Russian-made Syrian MiG-29 jet placed two Turkish F-16s patrolling the border under radar lock for several minutes. Later that day, Syrian surface-to-air missile batteries locked on to another flight of Turkish F-16s. The incidents place into stark relief the conflicting Syria policies of Ankara and Moscow. They also make clear the possibility of military confrontation, and throws another wrench into deconfliction talks between the United States and Russia.

This tension comes almost a week after Russia launched its air campaign in Syria to target rebels fighting the Bashar al-Assad regime, including some U.S.-backed groups. Turkey has already registered its displeasure with Russia’s new Syria deployment, and it has been lobbying its NATO allies for the creation of a “safe zone” in Syria for refugees. The zone, which Moscow opposes, would be roughly 90 miles east of Latakia – a regime stronghold and Russia’s main military base in Syria.

Turkey summoned the Russian ambassador on Monday, warning him that Moscow would bear responsibility for any further escalation. Turkish Prime Minister Ahmet Davutoglu played down the incident, emphasizing that there is no “crisis,” and that Ankara’s “channels with Russia remain open.” President Recep Tayyip Erdogan, however, struck a harsher note: “Russia is making a grave mistake,” he told reporters, calling the Kremlin’s actions “unacceptable.” The remarks were his toughest ever leveled at Russian counterpart Vladimir Putin, with whom he is known to have a close relationship.

Moscow called the airspace violation a “mistake,” assuring Ankara it would not happen again. But the targeted area, the village of al-Yamdiyyah, is only a few hundred yards from the Turkish border, and Russia’s well-trained pilots would have known that, given their airspeed, they would cross into Turkish airspace after dropping their bombs. The pilots would have also been aware that, since 2013, Turkish F-16s have downed three Syrian aircraft – a helicopter, MiG-23 fighter, and a drone – that have strayed into the same area.

Russian aircraft regularly probe NATO airspace to test their response. In this case, the jet that crossed the border was a Su-30SM – the only type of Russian aircraft in Syria designed to engage rival fighters – which suggests that the incursion was intentional. Indeed, NATO Secretary General Jens Stoltenberg said Tuesday that the incursion did not “look like an accident.” Its purpose was likely to simultaneously aggravate Turkey and flaunt Russian military activity in the face of NATO.

The Russian fighters also appear to have flown just out of range of NATO’s Patriot missile batteries in southern Turkey – missiles slated to be removed from Turkey later this month. Moreover, just 90 miles northwest of Saturday’s incident lies Incirlik Air Base, from where U.S. F-16s have been launching strikes into Syria since August – two of which recently had a close encounter with Russian fighters over Syria.

All of this suggests increased confidence on the part of Russian and Syrian forces amidst warnings from Turkey and its NATO allies. Calls from Ankara and Washington for the removal of Assad appear even more futile now that the Kremlin is providing the Syrian dictator with increased protection.

Patrick Megahan is a research analyst on military affairs at Foundation for Defense of Democracies, where Merve Tahiroglu is a research associate focused on Turkey. Follow them on Twitter: @PatMegahan and @MerveTahiroglu