
In the United States, for example, a contract entered into in California between a resident of California and a resident of Nevada, to be performed in Arizona, immediately raises potential conflict-of-laws issues regarding which state's law will govern the validity, interpretation, and performance of the contract. The ease of travel and commerce (by foot or by wheels) across these state lines makes such scenarios commonplace. In contrast, a contract between a Japanese and Filipino is less likely to occur as their interaction would necessitate the intervention of travel technologies like planes and ships. Of course, Philippine courts are competent to pass upon such disputes but that would be a question on jurisdiction. The confinement of interactions within the Philippine territory potentially reduces the complexity of legal issues and the need to determine which legal system applies.
Furthermore, the very nature of private international law stems from the movement of persons and property across state lines. The ease with which individuals can establish domicile or acquire property in different states or countries in land-linked regions inherently creates more opportunities for legal questions concerning jurisdiction, choice of law, and the recognition and enforcement of foreign judgments. A citizen of Texas can easily relocate to Oklahoma, potentially leading to disputes involving marital relations, conjugal property, inheritance, or tortious liability under Oklahoma law.
This relative scarcity of domestic conflict of laws jurisprudence partly explains why the study of private international law in Philippine law schools necessitates a deep dive into foreign case law. Landmark cases from the United States, such as Pennoyer v. Neff concerning the limits of state court jurisdiction, or Small v. United States concerning the effect of a foreign conviction, provide foundational principles that, while developed in a different geographical and legal context, offer crucial frameworks for understanding the theoretical underpinnings of conflict of laws.