In 1845, the republic of texas was annexed to the united states of america, becoming the 28th u. s. state. border disputes between the new state and mexico, which had never recognized texas independence and still considered the area a renegade mexican state, led to the mexican–american war (1846–1848.

The quote below is an excerpt from the charter of the united nations: "the purposes of the united nations are: to maintain international peace and security, and to that end: to take effective collective measures for the prevention and removal of threats to the peace, and for the suppression of acts of aggression or other breaches of the peace, and to bring about by peaceful means, and in conformity with the principles of justice and international law, adjustment or settlement of international disputes or situations which might lead to a breach of the peace . " source:this section implies that the united nations is prepared to do what to keep world peace?