Context: There are several reasons an otherwise valid and agreed upon treaty may be rejected as a binding international agreement, most of which involve problems created at the formation of the treaty.[citation needed] For example, the serial Japan-Korea treaties of 1905, 1907 and 1910 were protested; and they were confirmed as "already null and void" in the 1965 Treaty on Basic Relations between Japan and the Republic of Korea.

Question: When are most of the problems created that might result in an otherwise valid treaty being rejected as a binding international agreement?
Answer: at the formation of the treaty

Question: What treaties between Japan and Korea are examples of treaties that were declared null and void?
Answer: the serial Japan-Korea treaties of 1905, 1907 and 1910

Question: In what treaty were the serial Japan-Korea treaties of 1905, 1907, and 1910 confirmed as "already null and void?"
Answer: the 1965 Treaty on Basic Relations between Japan and the Republic of Korea

Question: Which two states signed a treaty that declared previous treaties between the two from 1905, 1907, and 1910 to be already void?
Answer: Japan and the Republic of Korea

Question: An otherwise valid and agreed upon treaty may be rejected as what for several reasons most of which involve problems created at the formation of a treaty?
Answer: a binding international agreement