The Qur’an does not allow polygamy except in certain exigencies such as war in which numerous men have been killed.
4:3 If you fear that you (the society) shall not be able to do justice with the orphans, (as may happen in times of war and political turbulence, the government shall announce a state of Emergency), then, in order to accommodate widows and orphans, men of sound finances and character shall be encouraged to marry these widows; two, three, and four (4:127). But, if you fear that you shall not be able to deal justly, then, you must not take additional wives, and may continue with what you already have (4:129). This will be more suitable to prevent you from doing injustice and face financial hardship.
[Second marriage during peace time is a frank violation of the Qur’an – note "If you fear that you (the society)" …]
At the time of Nikah, the Mullahs recite this ayah 4:3 and invariable drop the first words "IN KHIFTUM ALLA TUQSITU FIL YATAAMA" (If you fear that you shall not be able to do justice with the orphans). How cunning they are! And the bridal families never understand what is being done to them.