Read my answer here: https://apple.stackexchange.com/a/13285/34885 in the comments (look for my name: madivad). I can vouch, that iPhones warranties are NOT international.

IMPORTANT RESTRICTION FOR iPHONE AND iPAD SERVICE. Apple may restrict warranty service for iPhone and iPad to the country where Apple or its Authorized Distributors originally sold the device.

from https://www.apple.com/legal/warranty/products/ipad-english-a.html

Read my answer here: https://apple.stackexchange.com/a/13285/34885 in the comments (look for my name: madivad). I can vouch that:

iPhones warranties are NOT international.

IMPORTANT RESTRICTION FOR iPHONE AND iPAD SERVICE. Apple may restrict warranty service for iPhone and iPad to the country where Apple or its Authorized Distributors originally sold the device.

from https://www.apple.com/legal/warranty/products/ipad-english-a.html

UPDATE: I made this post in 2013, I have again checked the link above in 2017, and the situation is still the same.

Read my answer here: http://apple.stackexchange.com/a/13285/34885 in the comments (look for my name: madivad). I can vouch, that iPhones warranties are NOT international.

IMPORTANT RESTRICTION FOR iPHONE AND iPAD SERVICE. Apple may restrict warranty service for iPhone and iPad to the country where Apple or its Authorized Distributors originally sold the device.

from https://www.apple.com/legal/warranty/products/ipad-english-a.html

Read my answer here: https://apple.stackexchange.com/a/13285/34885 in the comments (look for my name: madivad). I can vouch, that iPhones warranties are NOT international.

IMPORTANT RESTRICTION FOR iPHONE AND iPAD SERVICE. Apple may restrict warranty service for iPhone and iPad to the country where Apple or its Authorized Distributors originally sold the device.

from https://www.apple.com/legal/warranty/products/ipad-english-a.html