"You break it, you own it," Colin Powell once warned in referring to U.S. military interventions overseas and the possible fallout that comes with those decisions.

The retired general and former secretary of state invoked his old rule in 2015 to explain his reluctance about the United States becoming too involved in the civil war in Syria. Powell, who served as chairman of the Joint Chiefs of Staff under President George H.W. Bush, highlighted the painful consequences of previous interventions elsewhere, including in Iraq and Libya.

It is a rule that some analysts say could apply to Russia as Moscow deepens its involvement in Syria.

After having intervened to save Syrian President Bashar al-Assad from being toppled, swinging the war definitively against the rebels just as his government appeared to be heading for defeat, the Kremlin has become more entrenched in Syria and owns the problem, say analysts.

If the Kremlin fails to secure a lasting peace, or is unable at least to stabilize the war-wracked country, still being buffeted by several micro-conflicts, then entrenchment risks turning into a potentially expensive entanglement that would undermine Russia's new regional clout.

And one of the biggest challenges Moscow will face, if the U.S. does withdraw ground troops from the country's northeast, as President Donald Trump has pledged, will be how to prevent a military clash developing between Syria and Turkey, they say.

FILE - This Dec. 11, 2017 file photo, Russian Pres FILE - Russian President Vladimir Putin, right, and Syrian President Bashar al-Assad watch troops marching at the Hemeimeem air base in Syria, Dec. 11, 2017. FILE - Russian President Vladimir Putin, right, and Syrian President Bashar al-Assad watch troops marching at the Hemeimeem air base in Syria, Dec. 11, 2017.

?Contradictory interests

According to analyst Aron Lund, Russia is balancing contradictory interests in Syria. The Kremlin wants to restore the central government and expand the writ of its client Assad across the country, including over the Kurdish-controlled northeast and an arc of territory from Afrin to al-Bab in the northwest now occupied by Turkish troops and rebel Sunni Muslim allies.

Turkey, a NATO member Moscow has been assiduously wooing, has its own designs on Syria, although they are as yet unclear. It has now threatened to cross east of the Euphrates River to attack Syrian Kurdish forces, which it says are aligned with Turkish Kurdish separatists. And Ankara shows no sign of being prepared either to give up its large position south of its border or to rethink its animosity toward the Syrian Kurds.

Western diplomats in Turkey's capital say Turkish officials have been lobbying the Kremlin to allow Turkish warplanes to use Syrian airspace, now under the control of the U.S.-led coalition against the Islamic State terror group, when the U.S. finally withdraws from the northeast.

"Turkey has never clearly defined its plans for the area, and Turkey shows no sign of wanting to relinquish the Afrin and al-Bab regions, and is working to shore up its hold on Idlib," Lund argues in a policy paper written for the Swedish Defense Research Agency. "Pulling NATO member Turkey out of America's embrace is a goal of major geopolitical significance to Russia. Putin's desire to court [Turkish President Recep Tayyip] Erdogan may in the end outweigh Assad's desire to retake outlying border regions now under Turkish control."

Erdogan has never made an explicit claim on northwestern Syria, but he has said Turkish troops and their Syrian Sunni allies, former anti-Assad rebels, will remain until Syria has conducted an election.

With peace talks stalled, and few signs of much progress toward a political settlement to the war, that in effect would delay for the foreseeable future Ankara's having to make any withdrawal decision. And in the meantime, the Turks are consolidating their grasp on the northwest — rebuilding schools, entrenching their own NGOs in the region and setting up municipal authorities.

Turkish President Tayyip Erdogan speaks during an FILE - Turkish President Recep Tayyip Erdogan speaks in Istanbul, Dec. 23, 2018. FILE - Turkish President Recep Tayyip Erdogan speaks in Istanbul, Dec. 23, 2018.

?What's next?

The question is whether Assad will remain patient. And if Assad seeks to shield Syrian Kurdish forces from Turkish attack, how restrained will Erdogan be in response?

On Tuesday, Erdogan invoked Turkey's Ottoman past when highlighting his military buildup. In a televised call to military commanders on the border as they stood outside the tomb of medieval Ottoman forebear Suleyman Shah, the president pledged to crush Turkey's enemies — Syrian Kurds and IS militants — and underscored his ambition to retain Syrian land under Turkish control, something that not only frustrates Damascus but Assad's other foreign backer, Iran.

Suleyman Shah's tomb was inside Syria but transferred closer to the Turkish border in 2015 after Islamic State militants threatened to destroy it. Erdogan has promised to return the tomb to its original site and said midweek that will be "an important harbinger." But of what he was not entirely clear. He added, "I believe your faith will bring many more victories. You've walked to the martyrdom and you are walking again. Allah will give us victory."

For weeks, the Turks have been amassing more military hardware along the border, including tanks, howitzers and armored personnel carriers. And inside Syria, Turkish-backed forces have moved closer to the strategic town of Manbij, controlled by Kurdish fighters, who until now have felt protected by the presence of U.S. ground troops. This past week, the Kurds turned to Damascus for protection, calling in Assad's forces into Manbij to deter a Turkish attack.

Juggling the interests and demands of both Damascus and Ankara while keeping Tehran satisfied is going to be a challenge for Russian President Vladimir Putin. He's also trying to prevent a potential clash between Israel, another Western-allied power he has been courting, and Iran in the south and west of the country.

FILE - Hulusi Akar, Turkey's defense minister and FILE - Hulusi Akar, Turkey's defense minister and former chief of staff, speaks with soldiers during a visit to Turkish troops stationed at the border with Syria, in Kilis, Turkey, Dec. 31, 2018. Russian and Turkish foreign and defense ministers met in Moscow two days earlier to discuss northern Syria as U.S. forces prepare to withdraw and Turkey threatens to launch a military operation against U.S.-backed Kurdish forces controlling nearly a third of the country. FILE - Hulusi Akar, Turkey's defense minister and former chief of staff, speaks with soldiers during a visit to Turkish troops stationed at the border with Syria, in Kilis, Turkey, Dec. 31, 2018. Russian and Turkish foreign and defense ministers met in Moscow two days earlier to discuss northern Syria as U.S. forces prepare to withdraw and Turkey threatens to launch a military operation against U.S.-backed Kurdish forces controlling nearly a third of the country.

?Moscow's control

"Moscow's permission for Ankara to use Syrian airspace enables Russia to set the pace and duration of Turkish military operations inside Syria," according to Metin Gurcan, a Turkish military analyst. Writing for the Al-Monitor news site, he said Moscow was able to control the pace in March of Turkey's assault on Afrin, closing down Turkish air operations for a week to allow Kurdish People's Protection Units (YPG) to withdraw from the border town without being targeted by the Turkish air force.

"Would Turkey dare use airspace in northeast Syria despite opposition by Moscow? No," said Gurcan. Otherwise it would not have sent a high-ranking Turkish delegation to Moscow last month to lobby for permission, he maintained.

Being the regional power-broker, as Russia now in effect has become, will test Moscow's juggling skills in a highly volatile corner of the world, say other analysts. Moscow could end up trapped in a quagmire.

"Though this new phase of the war has all the trappings of an endgame, some aspects of it may endure for the foreseeable future," said Lund. He added, "With external powers now dominating spheres of influence from which Assad cannot easily oust them, Syria's unsettled state may be turning into a frozen conflict where intermittent skirmishing and negotiations emerge as a new normal, and cease-fire lines gain permanency even in the absence of formal recognition."