Is the son's unwillingness to return to his home country, and his desire to remain in the country of study to marry and settle, considered disobedience to his parents, knowing that he does not intend to abandon them and fears returning to a country where bribery and deceit are prevalent, and he does not wish to work with his father due to past disagreements?

If your staying with your parents brings them comfort and does not cause you hardship in yourself or your finances, then it is better to fulfill their wish. However, if you experience hardship or a difficult livelihood by staying with them, there is no impediment to your residing in another country to earn a living, even if they do not permit it. But the ruling on residing in disbelieving lands remains to be considered.