Q&A: Why is Russia invading Ukraine?

Here's a look at how the conflict started and what has happened in the past few days

In this photo made from video provided by the Russian Defense Ministry Press Service on Saturday, Feb. 19, 2022, Russian marines take their position during the Union Courage-2022 Russia-Belarus military drills. Picture: Russian Defense Ministry Press Service via AP

For weeks the fear of a war in Europe has been growing with Russia making moves to invade Ukraine. Here's a look at how it started and what has happened in the past few days. 

How has all this started?