Russia has sparked worldwide condemnation over its unprovoked attacks on Ukraine. UN officials estimate that more than 4.2 million people have fled Ukraine since Russia invaded. And called it the fastest-growing refugee crisis in Europe since WWII. Ukrainian officials said thousands of civilians have been killed and injured in Ukraine. And experts are pointing to mounting evidence of Russia’s alleged war crimes. Dozens of countries have issued sanctions against Russia. And are helping Ukraine with weapons and humanitarian aid. But world leaders have also made it clear that this is Ukraine’s war to fight. The crisis is raising new questions every day. And we’re bringing you the answers. Starting with… Why did Russia invade Ukraine? There’s what Russia believes to be true…and then there’s what the majority of the world is saying. Russian President Vladimir Putin originally said the invasion would protect Russian speakers in two breakaway regions in eastern Ukraine — where he claimed there was “genocide.” But experts and President Biden believe Putin's likely goal is to "reestablish" the Soviet Union. Russia’s invasion came after months of rising tensions and the build-up of thousands of troops at its border with Ukraine. Psst…We have more on ‘the why’ behind the crisis here. Has Russia and Ukraine's relationship always been tense? It's been pretty complicated for a while. Ukraine and Russia were part of the Soviet Union before it collapsed in 1991. And Russia isn't a fan of its neighbor’s independence. The Kremlin has maintained that Ukrainians and Russians are “one people.” But Ukraine doesn’t feel the same way. And has been looking to join the Western military alliance NATO for years. A move that Russia believes would threaten its security since it would bring Western allies closer to its borders. And in 2014, relations between the two deteriorated even more after Russia annexed (read: took over) Crimea. More on that here. How have Ukrainians been impacted? In every way possible. Across Ukraine, ordinary civilians have volunteered in the fight against Russia. From cooking for soldiers, to making Molotov cocktails, to taking up arms. And their resistance efforts have made it harder for Russian troops to advance into cities like Kyiv. More than 4.2 million refugees have fled to neighboring countries — half of them are children. That amounts to more than 9% of Ukraine’s population of 44 million. Over 2 million people have fled to Poland — more than the population of the country’s capital Warsaw. Others have gone to Slovakia, Hungary, Moldova, Romania, and other European countries. It comes as UN officials have warned that Europe is facing an unprecedented refugee crisis. We've got more on this topic here. And how it’s sparking a larger conversation about racism in war. Has Russia committed war crimes? Human rights investigators say it appears that’s the case. And have called for an investigation. In March, the International Criminal Court first opened a probe into potential war crimes in Ukraine. But since then, allegations have grown louder. In April, Ukrainian officials found 410 bodies in towns near Kyiv after Russian forces withdrew from the area. Bodies were found on the street and in mass graves. And officials said some people appeared to have been shot in the head. Russia has denied the accusations. And while some countries are planning to respond with even more sanctions, it could be difficult to prosecute these alleged crimes. Here’s why. Why do I keep reading about humanitarian corridors? Because they’ve been attacked. Quick refresh: Humanitarian corridors are zones that allow civilians to safely evacuate areas that have been under heavy fighting. And give aid groups a chance to deliver things like food and medical supplies. All sides involved in the conflict have to agree on establishing these corridors. Since a cease-fire is required to set them up. But Ukraine has accused the Kremlin of violating cease-fire deals and killing innocent civilians. Humanitarian corridors previously opened long enough to allow thousands of people in cities like Sumy and Mariupol to escape. Meanwhile, Ukrainians officials had to close the corridors in late March amid fears that Russian forces may attack. Mariupol keeps making headlines. What’s the situation there? Russian forces have been trying to capture Mariupol for weeks. That’s because the southeastern port city connects Crimea (which is under Russian control) and parts of eastern Ukraine, where there are Russian-backed separatists. Heavy fire from Russian forces has left Mariupol in pieces. The city’s mayor said nearly 5,000 people have died. And officials have been warning of a brewing humanitarian crisis. Residents have had limited access to electricity, water, and food supplies for weeks. Some have even melted snow to get water. But Russia’s yet to take full control of the city. Is the US helping Ukraine? The US has more than 100,000 troops in Europe. Gov officials said 10,500 of them are in Poland. And in March, the Pentagon deployed another 240 Navy personnel and six aircraft to Germany to “enhance NATO's collective defense.” Congress has also approved $13.6 billion in emergency aid for Ukraine. All imports of Russian oil and gas energy — a major source of revenue for Russia — are now banned. And American skies are officially closed to Russian flights. Canada’s made similar moves. And provided $100 million in humanitarian and military aid in the form of aircraft, helmets, body armor, and personnel. What happened during President Biden's trip to Europe? The three-day trip consisted of him rallying allies in Brussels and visiting US troops in Poland. But some of his comments abroad landed him in hot water. During his trip, the president went off script and said Putin “cannot remain in power." Many interpreted that as the US calling for a regime change. The White House tried to backpedal and said ‘not true.’ Biden said he has “no apologies” about his comments. And that he was “expressing the moral outrage,” not articulating gov policy for a regime change. Meanwhile, a Kremlin spokesperson said “only Russians, who vote for their president” can decide who rules Russia. How’s Europe helping? In a number of ways. The EU’s providing $500 million worth in weapons to Ukraine (a historic move). And has banned “Russian-owned, Russian registered or Russian-controlled aircraft” from the 27-nation bloc. Ukrainian refugees will also be allowed to live and work in the bloc for up to three years. Several European countries have sent individual aid (see: Italy, France, Denmark, and the UK). And Switzerland broke with its tradition of staying neutral, agreeing to impose sanctions against Russia. Volunteers from around the world are traveling and arming up to support Ukraine. The PMs of Poland, Slovenia, and the Czech Republic have also visited Kyiv to meet with Ukrainian President Volodymyr Zelenskyy and show their support. Tell me more about Ukraine’s President Volodymyr Zelenskyy. He’s become a national hero in Ukraine and around the world. Zelenskyy was a comedian and played a teacher-turned-president in a popular Ukrainian TV show “Servant of the People." Now, he’s an IRL president who’s refused to abandon his people. The Ukrainian president has turned down the US’s evacuation offer, saying “I need ammunition, not a ride.” On March 16, Zelenskyy addressed members of Congress for the first time. And pleaded with US lawmakers to boost military aid, sanctions, and implement a no-fly zone. Weeks later, he spoke to the UN Security Council about the atrocities outside Kyiv. And called on the council to either revoke Russia’s membership or “dissolve” itself. That’s because Moscow is a permanent member of the Security Council and has veto power. Zelenskyy said Russian forces “must be brought to justice immediately.” You mentioned no-fly zones. How do they work? They’re pretty self-explanatory: It’s a region of airspace where certain aircraft are banned to prevent things like airstrikes or surveillance. In this case, Russian planes would be banned from flying over Ukraine. Meaning: They won’t be able to carry out air attacks. But since these zones are reinforced by military officials, they pose a problem for NATO and Western allies. Because they are not willing to deploy their forces out of fears that it could escalate the conflict with Russia. And Putin has warned that anyone who creates a no-fly zone will be considered a participant in the war. I heard Zelenskyy’s ready to offer neutrality. What does that mean? Neutrality means that a country’s military doesn’t form an alliance with others. (Similar to Switzerland.) In Ukraine’s case, it means the country would give up its goals to join NATO. Zelenskyy has said Ukraine would consider neutrality as part of a peace deal with Russia. But said any agreement would have to be voted on by Ukrainians in a referendum. In order for that to happen, Russian troops would have to withdraw. But Russia’s alleged war crimes have complicated negotiation talks. Have Russia’s plans in Ukraine changed at all? Russia said the first phase of its “special military operation” is over. And that it’s now focusing on controlling the eastern Donbas region. That’s where conflict between pro-Russia separatists and Ukraine has been ongoing for the last eight years. But Ukraine’s top military intel official said he believes Russia’s going another route — trying to split Ukraine in two. Kind of like North and South Korea. Meanwhile, Moscow also said it would “drastically'' decrease its military forces near Kyiv in order “to increase mutual trust and create the necessary conditions for further negotiations.” It all comes as Russia’s invasion has stalled there and in other major cities like Kharkiv. Is Russia feeling the effects of sanctions? Yes. The EU and US have basically launched an “economic war” against Russia — targeting oligarchs (aka the very wealthy), the country’s central bank, Russian banks, and gov debt. Russians have seen the ruble plunge 30% against the dollar — making it worth less than a US penny — at one point. And they’re seeing higher prices as the currency fluctuates. But experts say it could take years before Russia feels the full effects of sanctions on its economy. Learn more about how these penalties against Russia work. At the same time, dozens of companies have suspended or paused sales in Russia — another blow to the economy. Including McDonald's, Coca-Cola, Starbucks, and (many) more. It came after mounting public pressure for them to respond to the Kremlin’s actions. On March 28, Finland's national railway operator suspended its train services between St. Petersburg and Helsinki. And said it was in light of the Western sanctions on Russia. Since the invasion, trains have been packed with Russians trying to escape the country. Now, there’s one less option out there for people looking to leave. What about SWIFT? How is that impacting Russia? SWIFT — the Society for Worldwide Interbank Financial Telecommunication — facilitates transactions around the world. It’s kind of like Venmo. But with over 11,000 financial institutions. In response to Russia’s war on Ukraine, Germany, the US, and other countries agreed to remove some Russian banks from SWIFT. The move makes it harder for those Kremlin-run banks to get a hold of profits — including from trades on oil and natural gas (aka the country’s bread and butter). And adds to the historic sanctions imposed on the Kremlin. The goal’s to destabilize the gov and force its hand at ending the war. Psst…Here’s some quick facts about SWIFT. Is the war doing any damage to the US's economy? In a few ways. But most notably, with gas prices. In April, the national average price for a gallon still remained above $4 — high, but a lower price than some states have seen. In places like Los Angeles County, prices topped more than $6 a gallon at one point. The US hasn’t seen these high prices since 2008. We’ve got more on how the war can impact the US economy and your wallet here. Does Russia have any allies? At least one (so far): Belarus. Putin and Belarusian President Alexander Lukashenko are pretty tight. In 2020, Putin supported Lukashenko amid massive protests over the Belarusian leader’s “fraudulent” election. US officials said Belarus has become “increasingly reliant on Russia for economic, political, and military support in recent years.” And Belarus recently voted to give up its non-nuclear status — which could allow Russian nuclear weapons in the country. Before Russia invaded Ukraine, it used Belarus as a staging ground for Russian troops and weapons. Belarus also hosted talks between Russian and Ukrainian officials about potential cease-fires and humanitarian corridors (see above). A US official added that "it's very clear [Belarus’s capital] Minsk is now an extension of the Kremlin." US officials also believe that China’s open to supporting Russia. And said Beijing could provide military and financial assistance. The Kremlin asked for things like drones, ammunition, and non-perishable military food kits. It’s unclear if China will follow through on the requests. But the US has already warned Chinese officials that “there will absolutely be consequences” if they provide Russia a lifeline. Has Russia threatened to use nuclear weapons? Not explicitly. But Putin ordered his top defense and military officials to put nuclear forces on “special combat readiness.” It’s not very clear what that means. But the move could make it easier for Russian forces to launch nuclear weapons. It’s raising concerns about a potential nuclear crisis or new Cold War. Especially, since Russia holds the most nuclear weapons in the world. We explain everything you need to know about the Kremlin’s nuclear powers here. Is the US worried about Russian retaliation? The US’s tough sanctions could force Russia to retaliate. And some experts believe it could do so by launching cyberattacks against the US. (Because, reminder: Russian hackers have plenty of experience with attacking US infrastructure.) Biden has said the US is “prepared to respond” if the Kremlin tries anything. Our “Skimm This” team spoke with an expert about Russia's cyber capabilities and threat. Here’s what she had to say. Are Russian citizens supportive of the war? Many want an end to the conflict. And thousands have taken to the streets saying, “no to war.” Hundreds of those protesters have been arrested for speaking out. And now, they’re facing an intense crackdown on dissent. On March 4, Putin signed a new law that punishes anyone who spreads “false information” about the war in Ukraine. People who violate the law could face up to 15 years in prison. But that hasn’t stopped people like Russian journalist Marina Ovsyannikova. The sanctions affecting Russian banks are also impacting people’s ability to pay for things with Apple Pay, Google Pay, and credit cards. And tens of thousands of Russians have fled the country over fears of things like border closures, martial law, or economic hardship. Many have gone to Georgia, Turkey, and Armenia. Ballerina Olga Smirnova quit the famed Bolshoi Ballet company after denouncing Russia’s invasion. And has joined the Dutch National Ballet in Amsterdam. What about disinformation and propaganda? Disinformation about the Russia-Ukraine war has been spreading fast. In part because of social media. Clips of video games have been confused as IRL images of what’s happening in Ukraine. TikTok has suspended livestreams and new videos from being uploaded in Russia. And Facebook and YouTube have restricted some Russian state media outlets in Europe. We’ve got some useful tips on how to spot disinformation. Meanwhile, some Ukrainians have shared stories about how family members in Russia don’t believe the atrocities that are taking place. Some Russians have pointed to state media saying that Ukrainians are responsible for civilian deaths. And that Russia’s “special operation” is trying to help Ukraine. But in reality, that’s all Russian propaganda (aka lies). How can I show support for Ukraine? Here’s a list of verified resources you can use to give aid to refugees looking for shelter, LGBTQ+ Ukrainians, those fighting on the ground, kids suffering from the effects of war, and more. What can I do if I feel overwhelmed by all of this? We asked psychologist Dr. Carolyn Rubenstein for some advice. She explained why it may be hard to stop doomscrolling. And provided a few tips you can try if the crisis is affecting your mental health. theSkimm Many countries are united in their support for Ukraine. But are treading lightly in efforts to avoid escalating the conflict with Russia. It’s a crisis that the world is watching unfold. And one that will have ripple effects across nations. As new updates about the conflict cross your newsfeed, check back here to get your questions about the conflict answered. More Coverage of the Russia-Ukraine Conflict Still have more questions about the conflict? We've got you covered with… The Daily Skimm. Sign up to get the latest news on what's happening in Ukraine in your inbox every morning. "Skimm This." Listen to our news podcast for expert context on the crisis. Follow us on Instagram and Twitter for news updates. Updated April 7 to include the latest on Russia's alleged war crimes