first: the rules of the jam state that the moderators reserve the right to remove individuals at their discretion if the individual is being disruptive or bigoted. you aren't owed an explanation, but in the interest of giving you an opportunity for self betterment i will elaborate on my decision to ban you.
of the 4 messages you left in the server, the 2 most recent and inciting messages were charged with nationalistic sentiment. after the first message, i issued you a warning and brought the current discussion to an end. you went on to post a second message, doubling down on the sentiment.
if you're confused as to what content of the message could be construed as nationalistic, i encourage you to do some self reflection and reading on what exactly nationalism and fascism are, especially in relation to your own country. from there, examine the type of people that utilized arguments such as the one you presented, and to what end socially those arguments were leveraged.