A destroyed Ukrainian Army tank sits outside Uglegorsk southwest of Debaltseve. Photo: DOMINIQUE FAGET

MOSCOW: This is a critical week for Ukraine, as the White House deliberates whether to send arms, European leaders push for last-ditch peace talks, and war rages on the ground. More than 5300 people have died since the conflict started in April 2014, according to UNestimates, including hundreds in recent weeks.

After months in which the fighting had calmed, the conflict began to burn again in early January and has only grown worse in recent weeks. Rebels have been capturing large new stretches of territory and have threatened to mobilise up to 100,000 people in their fight against Kiev's forces. Western leaders appear to feel that now is the last chance to push for peace before a far more violent war envelops a broader part of Ukraine.

Why is there suddenly such noise about arming Ukraine, or putting a ceasefire in place?

War has been raging in eastern Ukraine since the middle of last year, but it had been calmer since early September. That's when pro-Russian rebels and the Western-oriented Ukrainian government agreed on a ceasefire that would have given separatist-held territories broad powers to rule themselves. Fighting never halted completely, particularly at the Donetsk airport, just outside the rebels' stronghold city. Ukrainian forces managed to hang on for months at the airport despite being outnumbered and besieged on three sides. But the airport fell on January 22, and since then the battle has raged with renewed strength. Rebel leaders declared the ceasefire null and void; they said they would try to capture vast stretches of new territory, raising fears of a bloodbath on European soil.

Why the focus on Russia, if the fighting is in Ukraine?

Because Russia is involved. Ukraine, NATO, the United States and the European Union have all said that the rebels are being supported with Russian equipment and troops. Russia has steadfastly maintained that it is not a party to the conflict, although Western journalists have interviewed Russian troops on Ukrainian soil and witnessed Russian heavy weaponry roll over the border. Western leaders clearly believe the keys to war and peace in Ukraine are to be found inside the Kremlin. So they have imposed a mounting campaign of economic sanctions against Russia. Now many policymakers in Washington say those tools have proven ineffective. They say the only effective way to bring about a peace settlement is by shipping defensive weaponry to Ukraine to make a Russian intervention far more costly.

What would happen if the United States armed Ukraine?

US policymakers have proposed shipping defensive weapons such as anti-tank missiles, surveillance drones and advanced radar to the Ukrainian army. President Barack Obama is considering it. Ukraine's army, never strong to begin with, is depleted by months of war against a better-equipped opponent. Proponents of arming the Ukrainian military say that if its troops had more powerful weaponry, they could more effectively stand their ground and could inflict a higher cost on the rebels and on the Russian troops believed to be backing them.

These proponents argue that Russian President Vladimir Putin does not want to risk significant losses of Russian troops. The evidence, they say, lies in the elaborate efforts the Kremlin made to hide the burials of Russian soldiers in late August and September, the last time Russian troops were in Ukraine in large numbers. With a more powerful Ukrainian army, the hope is that the rebels - pushed by the Kremlin - would sue for a more durable peace.

What could go wrong?

Opponents of arming Ukraine, including many European leaders, say that arming Ukraine risks adding fuel to the fire. Mr Putin could simply escalate his support for the rebels in return, and an even more violent confrontation could ensue, with dangerous and unpredictable spillover effects, the critics say. And it is a gamble to think that Mr Putin would hold back from broader support for the rebels simply because it was unpopular among the Russian people, they say. For one, Russia's powerful state propaganda could swiftly change minds. Mr Putin doesn't depend on public opinion to maintain control of Russia anyway, the opponents say. And the truly advanced weaponry that could shift the tide of battle is too advanced for the Ukrainians to operate themselves, they say. Does that mean sending US troops to run the equipment on the battlefield? Sending simpler weaponry that the Ukrainians could operate themselves runs a dual risk: it could escalate the war without being powerful enough for the Ukrainians to withstand Mr Putin's wrath.

What's the best-case scenario in Ukraine right now?

All sides say they want a ceasefire. The question is what terms could satisfy both the Kiev government and the rebels. Kiev is under heavy domestic pressure not to hand too much to the rebels. The rebels, meanwhile, have the initiative, and they would be hard-pressed to give up the hundreds of square kilometres of territory they have captured since the September deal. For now, the Europeans and Americans say those terms are the starting point of any negotiations. Mr Putin is said to have circulated a new document in the last week that suggests turning eastern Ukraine into a frozen territory similar to others in post-Soviet republics such as Moldova and Georgia. That would be a political non-starter for Kiev.

What's going to happen this week?

The White House may make a decision on arming Ukraine as early as this week. German Chancellor Angela Merkel, who is effectively leading the peace negotiations, met Mr Obama in Washington on Monday to discuss the current state of truce talks after flying to Moscow last Friday to talk to Mr Putin. Mrs Merkel, Mr Putin, Ukrainian President Petro Poroshenko and French President Francois Hollande plan to meet on Wednesday to continue talks. If those talks prove fruitless, EU leaders meeting on Thursday may move to impose broad new sanctions on Russia, and the conflict will keep burning.

Washington Post