mexican laws

Why can every other sovereign country have laws but the US is denied? Under Mexican law, illegal immigration is a felony. IF YOU CROSS THE NORTH KOREAN BORDER ILLEGALLY YOU GET 12 YEARS HARD LABOR. IF YOU CROSS THE IRANIAN BORDER ILLEGALLY YOU ARE DETAINED INDEFINITELY. IF YOU CROSS THE AFGHAN BORDER ILLEGALLY, YOU GET SHOT. IF YOU CROSS THE SAUDI ARABIAN BORDER ILLEGALLY YOU WILL BE JAILED. IF YOU CROSS THE CHINESE BORDER ILLEGALLY YOU MAY NEVER BE HEARD FROM AGAIN. IF YOU CROSS THE VENEZUELAN BORDER ILLEGALLY YOU WILL BE BRANDED A SPY AND YOUR FATE WILL BE SEALED. IF YOU CROSS THE CUBAN BORDER ILLEGALLY YOU WILL BE THROWN INTO POLITICAL PRISON TO ROT.