This article is so full of technical and legal holes, I don't know where to start.
1. The US continued to recognize The Republic of China (Taiwan) as the legitimate government of China until 1979 and continued to arm Taiwan.
2. The international community - as represented by the UN - also continued to recognize Taiwan as the government of China till 1971 and Taiwan held the status of permanent member till 1971, including Veto rights. So, by definition of any statute of limitations, Taiwan would be responsible party.
3. There is a 1979 agreement between the US and China for a mechanism for settling all claims between the two governments.
Here is the latest report from the US government which supports that all these claims have been settled.
3. It was in fact legally tested in the US in the New York federal court. The court threw out the case with two significant rulings.
First, since debt is a state subject and not a federal subject in the US, the court doubted its jurisdiction in this matter and accepted the case only because it dealt with "sovereign debt" but conceded that by being located in New York, it is bound by New York's statute of limitations which is 6 years. The significance of this ruling is that any future suit must be fought in a state court, not a federal court. The state of Kentucky has the longest statute of limitations in the US and that's 18 years. So, this can never be adjudicated in the US.
The case is called Morris vs the People's Republic of China and the full judgment is available here.
Second, the plaintiffs had bought the bonds for a few pennies (several years after the statute of limitations had expired); as such the court found that they have not experienced any serious harm or loss. The significance of this ruling is that the court implicitly agreed that the plaintiffs had no "standing" to sue. This ruling invalidates the argument that Obama, with a stroke of the pen can ask Security & Exchange commission to go after this debt, because the SEC has to represent somebody who has standing with a real grievance as defined by this federal court.
So, this article has little legal merit.