Editor’s Note: This is a guest post by Michal Thim responding to Julian Ku’s previous guest post on the Pacific Realist, which argued that Article 51 of the UN Charter on Collective Self-Defense would prohibit a third party from coming to Taiwan’s defense against China because Taiwan is not a UN member and countries like the U.S. abide by a “One China” policy. Ku did not argue that the U.S. or Japan should not come to Taiwan’s aid in the event of an attack, only that they couldn’t invoke Article 51 of the UN Charter in doing so.

Professor Julian Ku argues that helping Taiwan to defend itself is illegal. The core of his argument is that Taiwan is not an UN member, therefore– according to article 51 of UN Charter– it would be illegal for Japan or the U.S. to provide assistance to Taiwan should it find itself under attack by the People’s Republic of China.

Not so fast. Political scientists also have a few words to say on this matter. Taiwan is far from a clear cut case for us to apply a literal interpretation of the UN Charter.

First of all, it is not clear whether Professor Ku argues that non-members are international outlaws without any rights. Certainly a lack of UN membership does not mean that the respective non-member can be subject to armed attacks by other states as they please. Now, Taiwan is indeed not a UN member but it is not strictly speaking accurate to say that it is not a state. Here Taiwan’s status as the Republic of China recognized by some 21 states comes in play. While it is an argument that proponents of Taiwan’s independence would have a hard time swallowing, it gives Taiwan sense of international recognition.

From a de facto standpoint, it becomes even less ambiguous. Taiwan has territory, people (that even elects their government by democratic means, although that is not a requirement for sovereignty), government, armed forces, and it maintains relations with other states. Of course, Beijing’s position is that Taiwan is an integral part of China (i.e. the PRC) and therefore cross-Strait relations are not international relations. Yet, taking this position as a basis to asses Taiwan’s legality is extremely narrow and somewhat disingenuous if we consider the fact that Taiwan (or ROC) is not a UN member because Beijing opposes it.

Professor Ku finds Taiwan’s position worsened because, “Japan recognizes the government in Beijing as the rightful government of China, and Japan further recognizes that Taiwan is part of China.”

Beijing would certainly agree with this standpoint. However to argue that Japan recognizes Taiwan as part of China is not what Japan actually says. The 1972 Japan-China Joint Communique on this matter reads (emphasis added): “The Government of the People’s Republic of China reiterates that Taiwan is an inalienable part of the territory of the People’s Republic of China. The Government of Japan fully understands and respects this stand of the Government of the People’s Republic of China, and it firmly maintains its stand under Article 8 of the Potsdam Proclamation.” (Note: implication of Article 8 of the Potsdam Proclamation is that Japan gives up any territorial claims to Taiwan).

This is not dissimilar to the 1972 US-China Joint Communique (emphasis added): “The U.S. side declared: The United States acknowledges that all Chinese on either side of the Taiwan Strait maintain there is but one China and that Taiwan is a part of China.” The U.S. position is outdated only in one aspect: increasingly ‘The Chinese’ on Taiwan’s side of the Taiwan Strait overwhelmingly consider themselves not to be Chinese. China vehemently argues that any One China policy automatically means adherence to China’s interpretation thereof. Indeed, both the U.S. and Japan’s joint communiques contain the PRC’s position, but only along with the U.S. and Japanese positions respectively, i.e. expression of understanding, respect and acknowledgement, not a recognition. In other words, China has its interpretation of what constitutes One China, other sovereign states are rather keen to maintain their own, different, interpretations.

Professor Ku’s observations regarding U.S. commitments are equally problematic. The U.S. indeed declared that it would not feel obliged to assist Taiwan if it declares independence and consequently became subject to an armed assault by the PRC. But that is not strictly speaking a legal commitment. America may still may come to Taiwan’s help even if a Chinese attack is the result of Taiwan’s declaration of independence. After all, Professor Ku later observes that the U.S. maintains its policy as the one best suited to avoid military conflict with China. Yet, if the conflict erupts, the decision of the U.S. government will also depend on the context of the situation.

However, Ku’s argument implies that if China attacks without Taiwan having declared independence  China’s position would still be legal and (by definition) U.S. assistance would be illegal. The legality of China’s use of force is laid out as follows: “But that would be one state (China) using force within its own territory to put down secessionists (a la Ukraine) and almost certainly legal.”

But Taiwan’s case is not akin to Ukraine’s case. The Ukraine is responding to an immediate situation of armed insurgency. The situation (and international reaction) would certainly be different if parts of Ukraine that wish to secede entered peaceful negotiations and Kiev still decided to rely on force. Where the Taiwan scenario would fit in this picture is entirely unclear.

But let’s assume that U.S. and/or Japan would come to Taiwan’s help and China decides to sue them at the International Court of Justice. It is somewhat difficult to conceive that the only concern for the judges would be Taiwan’s non-membership in the United Nations. China would open a huge can of worms even by raising this issue (and it is unlikely anyway, given Beijing’s unwillingness to rely on international courts to settle its maritime claims).

Even if the court did accept the PRC’s standpoint—namely that Taiwan is an inherent part of Chinese territory—it would necessarily raise the question of whether it is okay to use brute military force against Taiwan’s population. At the beginning of the 20^th century this would be a non-issue as state sovereignty was much more absolute. However, since at least the beginning of the 21^st century the use of force even within one state’s borders is looked upon much less favorably. Indeed, as J. Michael Cole observes in his response to Ku’s argument, with the ethnic conflicts of the 1990s (Bosnia, Rwanda, Kosovo), an international legal concept of the Responsibility to Protect has emerged as a counterweight to the absoluteness of state sovereignty, especially in terms of a state’s right to use unrestricted violence against its own people.

The argument that helping Taiwan repel a PRC’s attack is illegal may very well be the literal interpretation of international law. Still, that is not a very useful approach to a situation that is not particularly clear cut– indeed rarely any matter between two sovereign actors is (Editor’s Note: Julian Ku did not argue that the U.S. or Japan should not defend Taiwan because of Article 51.) To apply a reading of Article 51 without any context does not tell us much about the possible legality of Taiwan’s defense (and third party assistance). International law requires not only reading the relevant provisions but also observing states’ behavior. In this respect, while Taiwan lacks general recognition, it is treated as if it is recognized in a wide range of practical issues, including visa-free arrangements, trade agreements, and weapons sales.

The bottom line is, without an ICJ ruling on this particular matter, or without previous precedent, U.S./Japan’s assistance to Taiwan is likely to be legal, although it’s hard to say one way or the other. In the end, the whole issue depends on whether Taiwan is a part of China or not, and that is a political, not a legal question. And a question that is open-end for many of the parties involved.