Generally clothing isn't copyrighted, and even if it was, the "1st sale" or exhaustion" doctrine would allow you to re-sell clothing you bought legally.
As for trademark infringement, as long as you don't misrepresent the brands you buy, don't misrepresent your lack of affiliation with the TM rightsholders, and as long as these are legitimate, branded products, you can sell them in Asia, or here in the U.S., or anywhere else you want. You don't need a license or consent from anyone.
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This is an issue that is largely going to be determined by the law in those countries; in particular, this is what is referred to as a "gray market" transaction. As far as U.S. law, the first sale doctrine will protect you from any trademark issues as long as you make appropriate use of the marks of the products you are selling.
Copyright issues can always arise for web marketing. For example, there is a common practice on eBay of taking other sellers pictures - every example of this is copyright infringement. However, what you are proposing does not seem to raise additional risks.
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This is legal so long as you are certain that the goods which you are selling are authentic (not counterfeit). But you have an absolute duty to make sure the goods are authentic---trademark infringement for trafficking in counterfeit goods is a strict liability offense---and your lack of knowledge that goods purchased at an outlet mall or discount store are counterfeit will not get you off the hook. Your most important task here is to make absolutely certain that the goods you sell online are legitimate.
Also, you need to be careful that you do not engage in commerce involving countries for which the U.S. has imposed economic sanctions or other such restrictions. Before selling to countries in Asia or elsewhere, you should retain counsel to advise you on this issue---you can get in a lot of hot water---potentially criminal, if you engage in trade with people in countries who are the subject of sanctions.
You have received good advice regarding authenticity and proper use of trademarks and non-infringement of copyrights. Double check those and be sure. A lawyer can help. More power to you if you can export to Asia. Most goods flow the other way, so there are lots of empty shipping container available for you heading that way. While to protect local industries, most Asian countries have little enforcement of IP against their companies who export, they tend to enforce IP regulations against goods coming into their countries to protect local industries, so get good legal help with international business law and export expertise.
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