First, it is the biggest attack on the country in its history.
Second, it is the most violent breach of the sovereignty of the EU and NATO members since the end of the Cold War.
In 2014, agents of the Russian military intelligence services GRU caused a massive explosion of 58 tons of ammunition in the Vrbětice ammunition depot area, killing two Czech citizens, threatening the safety of hundreds of people in the nearby villages, and causing damages in tens of millions of euros.
Arms and ammunition at the depot were destined for either Ukrainian forces fighting pro-Russian rebels or for rebels in Syria fighting the Russian-backed government.