How does one become ultranationalist? Much like other things, such as stealing, or even improving your skills at your sport, it is a process. If you surround yourself with ultranationalist ideas, and feed that mindset, you are well on your way to becoming ultranationalist.
Ultranationalism is extreme support for your country, which sounds absolutely great, until the next part, where being ultranationalist is also unconditional support for your country. Even if your country is wrong.
It's not rare for ultranationalist idaes to lead to genocides.
Unfortunately, due to corrupt powerful people (not necessary only the government), genocides are quite common. In the last decade (2011-2021), Mexico experienced 19 genocides. 3 of these genocides were committed by the government.
The biggest genocide in the last decade were the Durango Massacres, with a total of 340 fatalities. It was a part of the Mexican drug war, which has been going on since 2006.
Not a lot of information is publicized on this genocide.
The Tlatlaya Massacre in 2015 was the largest genocide committed by the government. There were a total of 22 civilian fatalities, murdered by government troops. The victims were 22 presumed criminals. In 2014, the troops were arrested. After the Human Rights Commission ran investigations, they realized that 15/22 of the criminals were murdered without authority. It also appears as though the troops may have altered the crime scene, making it look like the criminals were completely in the wrong. It seems as though they were released, due to lack of evidence.