By giving five more countries veto power, the Council could come to a stalemate.  This could mean that the council ends up deadlocked more often than not as was the case during the Cold war when the two blocs almost always opposed each other. Up until 1991 (from the UN founding in 1946) there were only 700 security council resolutions due to the deadlocked nature of the council. In the 20 years since there have been over 1300 resolutions.1 The negotiation process would also be significantly longer. As a result the peace and security of the world could be endangered by this step.  1 Wikipedia, United Nations Security Council resolution,