Let me ask you a blunt question to understand your headspace: Am I committing a crime if I cross South Korea border and stay over there without any form of consent? And more that the technicality of the crime, is it morally fine to do so?
https://www.law.cornell.edu/uscode/text/8/1325
https://elaw.klri.re.kr/eng_mobile/viewer.do?hseq=61640&type...
You can find similar laws for the majority of other first-world countries too.