Antisemitism is the hatred of Jews, Judaism, and can include hatred of the Jewish State.
Antisemitism exists in many forms from stereotyping to scapegoating to violence or even the desired erasure of the Jewish people. It targets Jews, individually and collectively, and has adapted over time to falsely link Jews to whatever the societal ills of the era may be.
Antisemitism did not end with the horrors of the Holocaust.
The hatred of Jews persists in the twenty-first century in both overt ways – like a shooting at a synagogue or a swastika painted on the side of a building, and subtle ways – such as the perpetuation of Jewish stereotypes or retaliation against Jews in America and Canada for the acts of the Israeli government.
You are not antisemitic if you don't support the State of Israel.
However, if Israel is the only country that you demonize, delegitimize, and hold to a double standard, these views may be rooted in antisemitism. Often anti-Israel sentiments are used to justify the hatred of Jews writ large or prejudices against Jews are used to demonize the State of Israel. These are both forms of antisemitism.
Hatred of Jews is not solely a Jewish problem. Antisemitism is a sign of an intolerant society.
All individuals should care about antisemitism in order to build a society that is more compassionate, educated, and committed to the value of human dignity. Making hatred of Jews socially unacceptable requires Jewish allies to be invested in creating a more compassionate and caring community.