I think about this issue because what is Kuffar dress? And is this really Kuf'r?
Shaykh (Maulana) Ashraf Ali Thanwi (RA) [1863-1943] on wearing Jackets and other Western styled clothes (in London etc)
Discussion 1:
I had this discussion with Brother Umar in my house but this is his post on Sunniforum
Is wearing a jacket in London regarded as tashabbuh?
A person asked whether the wearing of a jacket by a Muslim living in London would be regarded as tashab-buh or not? The reply was that this is not tashab-buh because over there this item is not regarded as the specific dress code of the non-Muslims. Everyone dresses the same, hence there is no distinction. If this jacket becomes common here too, such that no importance or significance is attached to it, then the prohibition in wearing it (here) will be removed. [Hasanul Azeez, page 213, vol. 3]
Discussion 2:
In Imadaul-Fatawa (Volume 4/Question 345) it states:
Q:) In this country (UK) what is the status of adopting their clothing so one doesn't appear strange, is that a sin? What if a person adopts their dressing and external appearence not by his liking but to reduce the amount of strange (looks) so even kids don't laugh at him in the streets, would this (intention) reduce the burden of sin?
A:) It is my understanding that in India dress is a sign of distinct nationality and it would fall under tashabuh bil kuffar (likeness to the disbelievers) but where the dress code is National and where all ethnicities and (people of all) religions wear the same dress then wearing such clothes (there) will not be a problem. Now you need to judge the local situation based on the principle (given).