Which country has the largest international border?

Russia and China each border 14 countries. Brazil is a distant 2nd bordering 10 countries. Here is a list of what each country borders.

Russia: Azerbaijan, Belarus, China, Estonia, Finland, Georgia, Kazakhstan, Latvia, Lithuania, Mongolia, North Korea, Norway, Poland, and Ukraine. (This is if you count Kaliningrad, which, although it is not connected to Russia, it is part of Russia nonetheless. If you don't count them as being one together, then Poland and Lithuania do not border Russia.)

China: Afghanistan, Bhutan, India, Kazakhstan, Laos, Mongolia, Myanmar (Burma), Nepal, North Korea, Pakistan, Russia, Tajikistan, and Vietnam.

Brazil: Argentina, Bolivia, Colombia, French Guiana, Guyana, Paraguay, Peru, Suriname, Uruguay, and Venezuela.

Well, there you have it, and a little extra, your most bordered country.