Kazakhstan shares land borders with Russia, China, Uzbekistan, Turkmenistan, and which other country?

The correct answer is Kyrgyzstan. Kazakhstan's complete set of land neighbours numbers five countries: Russia to the north, forming the world's second-longest continuous international border; China to the east; Uzbekistan and Turkmenistan to the southwest; and Kyrgyzstan to the southeast. The Kazakhstan-Kyrgyzstan border runs along the Tian Shan mountain foothills and is the shortest of Kazakhstan's five borders, but it is nonetheless a genuine, internationally recognised frontier connecting the two Central Asian republics. None of the three distractors actually border Kazakhstan. Tajikistan, the first distractor, is a Central Asian neighbour of Kyrgyzstan and Uzbekistan, but a narrow strip of Uzbek and Kyrgyz territory separates it from Kazakhstan, so the two countries do not share a direct boundary, a subtlety that trips up candidates who lump all five '-stan' countries together as mutually bordering. Afghanistan, the second distractor, lies further south, bordering Tajikistan, Uzbekistan and Turkmenistan, but it is not adjacent to Kazakhstan at all, being separated by these other Central Asian states. Mongolia, the fourth distractor, lies to the east of Kazakhstan but is separated from it by a stretch of Chinese territory (specifically Xinjiang), so despite being a fellow steppe nation in a similar part of Asia, Mongolia does not physically touch Kazakhstan. A common exam confusion is assuming that because Kazakhstan, Uzbekistan, Turkmenistan, Kyrgyzstan and Tajikistan are collectively known as the five Central Asian '-stan' republics, every pair among them must share a border, when in fact Tajikistan does not directly border Kazakhstan. The revision takeaway is to fix Kazakhstan's five real neighbours as Russia, China, Uzbekistan, Turkmenistan and Kyrgyzstan, and to remember that Tajikistan, Afghanistan and Mongolia, though regionally close, are not among them.