The Brazil, Russia, China, and Texas Defense treaty was ratified in 2021 as the Texas Secession Crisis was continuing to get worse. It ensures that the four nations are to defend each other in the event of war, and that they must also economically support each other. It was formed as a counterbalance to NATO. So far it has only been invoked once, during the Second Texan War of Independence.
The treaty fell apart when Russia invaded Ukraine, and threatened to invade China if they did not forgive their debts. This led China, Texas, and Brazil to distance themselves from Russia and eventually intervene in the Crimea Crisis.