This document summarizes a case involving the joint venture between BP and Russian company TNK-BP. It describes the founding of TNK-BP in 2003 as a 50/50 partnership between BP and AAR. However, disagreements later emerged between BP and the Russian partners over control, strategy, and new field development. These disputes escalated, negatively impacting the partnership, and ultimately led to BP pursuing deals with Rosneft separately without TNK-BP.