The war between Russia and Ukraine may seem to some foreign onlookers as an astonishing and unprompted turn of events, especially to those who are not familiar with the international politics surrounding Russia’s invasion. However, with continuous news coverage of the war, multiple prominent figures and organizations endorsing Ukraine, somewhat surprisingly including comedy television show Saturday Night Live, and international criticism and denunciation of Russian President Vladimir Putin, it is nearly impossible to be ignorant of Russia’s invasion of Ukraine. This then leads many onlookers to ask: why is Russia invading, and what prompted Russia’s claims over Ukraine, or portions of it?

To begin, Russia has currently given two different reasons regarding their attack on Ukraine. Putin has said that he is moving to protect Ukrainians and Russians on the Russia-Ukraine border who have seceded from Ukraine and called for Russian aid after being attacked by Ukraine. Putin also claimed that he is attempting to deNazify Ukraine, which comes directly in contrast with Ukraine’s elected President Volodymyr Zelenskyy, who is openly Jewish. So, why does Putin feel confident in claiming that Ukraine is a Nazi state?

After the Ukrainian People’s Republic, formed in 1917 after splitting from the Russian Empire, was defeated by and absorbed into the Soviet Union, Ukrainian nationals were punished for resisting Soviet attempts to collectivize within Ukraine. This punishment came in the form of mandates and force by the Soviet government that created a man-made famine—Holodomor, a term that combines the Ukrainian words for starvation and inflicting death. Approximately 13 percent of the Ukrainian population, or 3.9 million people, died because of these measures, which boosted Ukrainian nationalism and movements to separate from the Soviet Union.

During World War II, then-Nazified Germany invaded the Soviet Union, including Ukraine. Many Ukrainians saw the German army as liberators from the Soviets, and though they did not want to be occupied by Germany either, they saw it as a means of escaping Soviet control. During this period of occupation, Ukrainians did aid German forces in the Holocaust, and it is believed that one in every four Jewish victims of the Holocaust died in Ukraine. This is why Putin claims Ukraine is a Nazi state, but it doesn’t fully explain how the invasion of Ukraine began.

In 2014, the Russian Federation invaded Crimea and annexed the peninsula from Ukraine. This was done using underhanded tactics in efforts to reclaim lands that once belonged to the Russian Empire and the Soviet Union. The similarities between Russian tactics in the Crimean Peninsula and their current engagement with Ukraine is staggering, to say the least. Russia faced sanctions from multiple countries, and their annexation of the Crimean Peninsula was condemned internationally, including by Ukraine. Similarly, Russia is now facing sanctions globally, including by famously neutral countries such as Switzerland, and even the Russian public are condemning the actions of their government, though it is impossible to know whether these protests will have any effect on the Russian war effort.

While we don’t know where the war will go from here, the history behind this war is one of two countries that have been in conflict with each other in various ways for over a century, and regardless of your beliefs regarding the war, the devastation in Ukraine is undeniable. Civilians are being killed and having to resort to extreme tactics to survive, and that is a tragedy that cannot be understated. It is encouraged that you research the war and ways you can help civilians caught in the crossfire. CNBC has compiled a list of the highest rated charities you can donate to that support Ukrainians in various ways, from food to medical supplies and more. If you can, please donate and support Ukrainians during this costly, devastating war.