The leaders of Russia, Ukraine, France, and Germany gathered on Wednesday in Minsk, the capital of Belarus, to try to broker a peace agreement after 10 months of conflict that has claimed more than 5,000 lives and set the stage for a protracted proxy war, with the U.S. and NATO forces on one side and Russia on the other.

Even as the world leaders convened, violence flared in eastern Ukraine, underscoring the critical need to reach an agreement.

"There is no military solution to this conflict, only a political one; and a new supply of U.S. arms will provide ammunition for Russian leaders who believe, fairly or not, that America is attempting to turn Ukraine into a military base near Russia’s borders."
—Katrina vanden Heuvel, The Nation

As he arrived in Minsk, Ukrainian president Petro Poroshenko said: "Either the situation goes down the road of de-escalation, ceasefire ... or the situation goes out of control."

According to the New York Times:

Negotiations on what exactly the leaders would discuss continued even as the various governments announced that their leaders were heading to Minsk. The talks are based on a 12-point peace agreement called the Minsk Protocol, signed here in September but violated almost immediately.

A group of negotiators from Russia and Ukraine, as well as from the separatist strongholds of Donetsk and Luhansk, were trying to make the final arrangements for a cease-fire and the size of a demilitarized zone, according to a Ukrainian diplomat who spoke on the condition of anonymity because he was not authorized to discuss the talks.

While details of the potential deal haven't been released, the Associated Press explored key sticking points at the talks, including:

• Drawing a new line of division: Ukraine wants the same one that was agreed upon in September, while Russia wants a new line that reflects the rebels' significant territorial gains since then.
• Withdrawing Russian troops and equipment from eastern Ukraine: Russia says it does not have any troops and military hardware in the east, a stance scoffed at by Ukraine and NATO.
•  Securing the Ukraine-Russian border: Ukraine wants to get control back over its border with Russia to stem the flow of Russian fighters and weapons, while Russia says that's up to the rebels who have captured some key border posts.
• Giving the separatists more autonomy: Ukraine says it may offer them broad rights under Ukrainian law but Russia wants guarantees. Russia also wants Ukraine to end its financial blockade of the east.

German chancellor Angela Merkel "has emphasized repeatedly since she announced the renewed peace initiative last week that the chances of success were slim," the Times added. And French foreign minister Laurent Fabius told France Inter radio, "It is really a last-chance negotiation."

"Still, Moscow expressed optimism," Reuters reports. "A Russian diplomatic source said it was 70 percent likely that an agreement would be reached."

The Telegraph is live-blogging the proceedings in Minsk.

Meanwhile, in a one-on-one phone conversation Tuesday, U.S. President Barack Obama personally warned Russian President Vladimir Putin that unless an acceptable peace deal is reached in the talks, Russia will face increased costs for its encroachment into Ukrainian territory and its continued support of separatist rebels.

Earlier in the week, Obama confirmed that he has asked aides to provide him with options for dealing with the ongoing violence in Ukraine, including the possibility of providing weapons to the Ukrainian military.

Analysts have raised questions about both the ethics and efficacy of sending U.S. weapons to Ukraine.

Shipping advanced weaponry to Ukraine "would be a huge mistake for the United States, NATO and Ukraine itself," University of Chicago political science professor John J. Mearsheimer wrote on Sunday. "Sending weapons to Ukraine will not rescue its army and will instead lead to an escalation in the fighting. Such a step is especially dangerous because Russia has thousands of nuclear weapons and is seeking to defend a vital strategic interest."

"Because the balance of power decisively favors Moscow, Washington would have to send large amounts of equipment for Ukraine’s army to have a fighting chance," Mearsheimer continued. "But the conflict will not end there. Russia would counter-escalate, taking away any temporary benefit Kiev might get from American arms."

"Sending weapons to Ukraine will not rescue its army and will instead lead to an escalation in the fighting. Such a step is especially dangerous because Russia has thousands of nuclear weapons and is seeking to defend a vital strategic interest."
—John J. Mearsheimer, University of Chicago

In a piece published at the Washington Post on Tuesday, The Nation editor Katrina vanden Heuvel echoed such concerns.

"[A]rming the Ukrainian military is not in the best interest of the United States, nor is it in the best interest of Ukraine," she wrote. "It will only worsen a bloody crisis that has already claimed thousands of victims. As I have argued in the past, there is no military solution to this conflict, only a political one; and a new supply of U.S. arms will provide ammunition for Russian leaders who believe, fairly or not, that America is attempting to turn Ukraine into a military base near Russia’s borders."

The U.S. should apply lessons learned in other conflicts to its deliberations over Ukraine, said Trevor Timm, co-founder and the executive director of the Freedom of the Press Foundation, at the Guardian:

[G]iven that U.S. weapons from its various ill-conceived arming operations have been found in the hands of Isis in Iraq and in Syria—and just recently, that $400 million of military equipment to Yemen seems to have fallen into the hands of rebels the U.S. considers its enemy—maybe just this once we should consider the consequences of sending weapons first and asking questions later. Helping to escalate a military confrontation against the nation with the largest nuclear weapons supply in the world could have some consequences beyond the simple front page photograph of Russian-backed soldiers triumphantly holding up captured American-made weapons.

Also Wednesday, U.S. Army Europe Commander Lt. Gen. Ben Hodges said that in March a battalion of U.S. soldiers would train three battalions of Ukrainians on how to better defend themselves against "Russian and rebel artillery and rockets."