Although I do not believe that our new understanding of dolphin intelligence results in the implementation of International law, all animals should be protected by laws regardless of their level of intelligence. However, as long as they are living creatures, they must have rights to live as they like as rights that people obtain protect them from unreasonable violence and death.
In modern society, many of animals are badly treated and even violated by humans, which should be prohibited by International law regarding their treatment. Dolphins that are considered to be very smart is a case in point. Dolphins especially in Japanese aquariums are often used for ones entertainment, “Dolphin show”. For this, dolphins are more likely to be forced to live in captivities. What is worse, exploiting their intelligence, dolphins are often trained strictly for shows. They are only under human control. In this way, dolphins, animals as a whole should secure their freedom with the aids of international law considering their treatment.
Although the question points out intelligence itself proves the necessity of International laws on animals, this concept is too unfair. In this theory, more intelligent animals have to be treated better than less intelligent animals, which is totally unreasonable.
In conclusion, I argue that it is completely necessary to implement that kind of laws regarding current conditions surrounding all animals. To achieve fair world both for all being, we are required to abandon the concept of intelligence.