There is an age-old consensus among Muslims that concludes that polygamy is permissible. The condition which Islam lays down for permitting a man to have more than one wife is that he has confidence on his part that he will be able to deal equitably with his wives in the matter of providing food, housing, clothing, and expenses, and that he will also be able to divide his time between them. Any man who doubts that he will be able to fulfill all these obligations with justice and equality would be prohibited by Allah Almighty from marrying more than one woman. Further, a Muslim is prohibited to abuse this right. For Muslims living in non-Muslim lands, polygamy may not be practiced if it is illegal in a person’s country of residence. So a Muslim living in those countries has to abide by such laws and not to violate them as long as he resides in that country.

Sheikh Muhammad Nur Abdullah, president of the Islamic Society of North America (ISNA) and member of the Fiqh Council of North America, states the following: The relationship between a husband and wife is based on ma`roof or kindness, compassion, and mercy. Both husband and wife are supposed to work at pleasing each other and dealing kindly towards each other.
When it comes to the rights of both men and women in Islam, we should believe that Almighty Allah is the JUST and the WISE. So He only gives people what is good for them and only demands what is for their interest and common good. The problem is that we sometimes look very selfishly and try to have all the good for ourselves without looking at the society at large.
as for polygamy, it is allowed in Islam. It is to be used for the purposes for which it is permitted and not to be abused in any case. It is true that Allah permits the man to marry four wives, but if we think in neutral terms and try to investigate the benefit of that without thinking only of our own interests, we will find the wisdom and significance of polygamy.
For example, if a wife puts herself in the shoes of a widow who does not have anyone to care for or look after her, and thinks sincerely of a solution to her problem, she will find that she would love to be a second wife rather than to stay as a widow and continue to suffer the problems in raising children and having the same life as her peers do. So there is always wisdom behind polygamy.
as for hurting the feelings of the first wife, I personally believe that a husband should discuss this issue with his wife and they should both reach a reasonable agreement. If the wife finds herself unable to accept her husband taking another wife, she has every right to demand divorce and to get her rights fully and separate in kindness. But if she thinks reasonably and not emotionally and weighs the pros and cons of being divorced or of being a cowife, she would be able to reach a better conclusion to save her family life and marriage.
This does not mean men are allowed to abuse the practice of polygamy. It is only allowed for whoever is able to treat all wives equally and fairly. If he cannot be just and fair, it would be forbidden to take another wife.