This is a question often asked. Recently a person asked this in a comment in Facebook. I thought I will archive my reply to it for future reading by anyone.
To get an answer the question on Vali, you just have read further in the Ramayana. Vali asks the question. Rama gives the answer and Vali is satisfied with the answer. Vali appreciates Rama’s understanding of Dharma and gives Angada into Rama’s protection. That shows that Vali does not see it as adharma.
Some of the reasons are:
– Dasharatha (one whose chariot goes unobstructed in 10 directions), true to his name was emperor. So there is no region outside his rule, though some regions like Dandaka Aranya were temporarily occupied by Maricha, Subhahu, etc. Rama being the son of Dasharatha has all the rights to ensure dharma using all the means available. On the top of that, the boon of Kaikeyi was – let Bharata rule over the cities and let Rama rule over the forests for 14 years.
– Rama being a Kshatriya, under the authority of the Veda, which is accepted by the whole Bharata Varsha (including Kishkinda and Lanka), has the right to take to task the wrong doings of any king anywhere in Bharata Varsha. (Like countries going half-way round the earth to establish human rights)
– If Vali is considered as a civilized person, he should honor the rules of civilized society like marriage, brotherhood, etc. If Vali is considered as an animal, a Kshatriya has the right to kill an animal as sport. (This was an allowance given to maintain the grit and valor of Kshatriyas during times of peace and also there were an abundance of animals in the forest.)
– To establish Dharma, a Kshatirya can do whatever needed. For example, a police car can violate the speed limit to intercept a speeding rogue car. If the police car follows the speed limit, the rogue car can never be intercepted. This is the case with Vali. He has a boon that half the strength of anyone who fights in front of him would come to him. So a Kshatriya has the right to strategize.
– Vali being the current king, if a war is declared, he will first send the monkey army. Only after fully finishing off the army, Rama will even get a chance to fight Vali. Even if he kills Vali then, what Sugriva would get is a country whose army has been destroyed by Rama. Also, the monkeys in the army are innocent. Rama did not want such destruction.
– Rama had promised to Sugriva that Vali will not see sunset. To keep up his promise, Rama is ready to be even take the name of “coward”. To Rama, keeping up the word is more important than the name as “brave”.
These are only some of the discussion in Ramayana. You just have to read more deeply. Your question and many more that you can think of are raised and answered. If you still have a different question, you need to approach a person like Krishna Premi Maharaj or some traditional authority. They will be very happy to answer your question.
The same is the case with all the so-called controversial questions like “Rama going to exile”, “Sita entering fire”, “pregnant Sita being abandoned”, “Drona taking Ekalavya’s thumb”, “Yudhisthira playing game of dice”, etc. The original texts themselves have elaborate discussions on these topics. You just need to read further or ask a traditional teacher. Never approach modern storytellers for these. We have a very good rational intelligent tradition who would give the answers in the spirit of the original book.