Q. Thalweg Doctrine, which was in news recently, is related to which of the following?
Answer: Water Bodies
Notes: Thalweg Doctrine is a part of international law that aims to resolve water boundary disputes. The doctrine states that the boundary between two states divided by a flowing body of water may be drawn along the thalweg, which is the line of the greatest depth of the channel. The boundary would follow the center of the principal navigable channel of the waterway. The Thalweg Doctrine has been used in several disputes, including:

1. The Shatt al-Arab between Iraq and Iran
2. The Danube in central Europe (Croatia–Serbia border dispute)
3. The Kasikili/Sedudu Island dispute between Namibia and Botswana
4. The 2004 dispute settlement under the UN Law of the Sea

The Thalweg Doctrine has also been used in the Sir Creek dispute between India and Pakistan. The dispute is not settled yet due to a lack of trust.