Legal analysis: (1) The damage is caused by foreign international illegal acts. An internationally wrongful act refers to an act that violates a country's international obligations and can be attributed to that country.

(2) The protected person has the nationality of the protecting country, which is the so-called "nationality continuity principle". In addition, the principle of "actual connection of nationality" has been put forward in international practice recently, which requires the victim to have actual connection with his country of nationality;

(3) Exhausting local remedies. That is, before the country of nationality puts forward diplomatic protection for the injured natural person or legal person, the injured natural person or legal person must first exhaust all legal remedies provided by the responsible country through ordinary or special judicial or executive yuan or institutions. Diplomatic protection can only be put forward if these means are not reasonably relieved, which is the principle of "exhaustion of local remedies"

Legal basis: article 14 of the draft articles on diplomatic protection (1), unless there are circumstances stipulated in draft article 15. Before all local remedies have been exhausted by the injured person, a State may not make an international claim against its nationals or other persons referred to in draft article 8.

2. "Local remedies" refers to legal remedies available to victims through ordinary or special judicial or administrative courts or institutions of the country allegedly responsible for the damage.

3. When making an international claim or making a declaratory judgment related to the claim mainly based on the injury suffered by a national of a country or other persons referred to in Article 8, local remedies shall be exhausted.