Russia’s invasion of Ukraine one year ago marked the beginning of the deadliest war in Europe since World War II and heightened U.S.-Russia tensions to a level not seen since the Cold War.

Both the Ukrainian and Russian people have suffered tremendous losses while the war has rattled the global economy and shaken up the international order.

Here are answers to five common questions about the ongoing war.

When did the Ukraine war start?

Russia invaded Ukraine in the early morning hours on Feb. 24, 2022. Moscow had been massing troops at the borders for weeks.

But the roots of the conflict actually go back nearly a decade. 

Why did Russia invade Ukraine?

To understand why Russia launched a conventional war with its neighboring country, you have to understand a bit of history.

When the Soviet Union collapsed in 1991, member nations, including Ukraine, broke up into independent states.

At the turn of the century, Russian President Vladimir Putin, a former KGB officer, won election for the first time. Putin, who has railed against the U.S. and the Western security alliance NATO, has sought to reclaim Russian might and restore his country as a great power. He has served as either president or prime minister of Russia since 2000.

At the same time, Ukraine was slowly moving toward joining the Western economic bloc, the European Union. 

In late 2013, when pro-Russian President Viktor Yanukovych suspended plans to sign an association agreement with the EU, Ukrainians erupted in protests called the Maidan Revolution that eventually forced Yanukovych to flee the country.

In 2014, Moscow reacted by illegally annexing the Crimean Peninsula and fomenting a rebellion of separatists in the eastern Donbas region.

Ukrainian troops and Russian-backed separatists have fought in the Donbas region ever since.

In December 2021, shortly before the invasion, Russia also submitted a list of demands to NATO that included rolling back military activity in eastern Europe. 

The demands were rejected by the alliance.

Is the Russia-Ukraine war over?

No.

One year in, Russian forces and Ukrainian troops remain locked in tense combat in eastern Ukraine.

But the war has condensed. Russia sent troops marching toward Kyiv in western Ukraine at the beginning of last year, before its forces were pushed all the way back to the eastern part of the country in the ensuing months.

Still, Moscow conducts regular missile and drone strikes that hit critical infrastructure in cities across Ukraine.

When will the Russia-Ukraine war end?

Bringing an end to the war will depend on several nations and government leaders, as well as various extremely complex factors.

As such, it’s too hard to tell at this point in time when the war might end.

Both Ukraine and Russia remain firmly entrenched in their positions and are unlikely to budge on any negotiations.

Ukrainian President Volodymyr Zelensky has vowed to retake all territory occupied by Russia, including the Crimean Peninsula.

And Putin is unlikely to give up the four territories he illegally annexed last year: Luhansk, Donetsk, Zaporizhzhia and Kherson.

Peace proposals and attempts to get officials from both sides to the negotiating table have failed. 

There’s also a lingering question of whether U.S. and NATO allies should engage in separate negotiations with Russia.

Who is winning the Russia-Ukraine war?

The war has brought victory for neither side, only deep suffering, death and a mass wave of refugees.

Still, Ukraine has won multiple, decisive battles and has inflicted serious casualties on the Russian army. By some U.S. estimates, Russia has lost around 200,000 troops.

In the first phase of the war, Ukrainian troops pushed Russia out of the western part of the country.

The second phase saw Russia condense operations in the eastern Donbas region, made up of Luhansk and Donetsk. Russia also has fortified positions in occupied Zaporizhzhia.

In the third phase, Ukraine carried out successful counteroffensives that liberated the southern region of Kherson and most of northeastern Kharkiv.

Brutal fighting continues mostly in Donetsk and Luhansk. Russia launched a massive offensive to retake the Donbas this month but has struggled to make significant progress.

Ukraine is likely to launch a counteroffensive of its own in the coming months.