The factor that does not influence a country's foreign policy is the age of the leader. Economic considerations, such as attracting foreign investments, international law, conventions and treaties and cultural factors, including religion and race, can play a significant role in foreign policy decisions.
While the experience, personality, and vision of a leader can influence foreign policy, the leader's age alone is not a direct factor in shaping a country's foreign policy. It is the leader's policies, decisions and diplomatic strategies that matter, not their age.