Both countries were involved in a system if alliances.
It prohibits any laws that establish a national religion, impede the free exercise of religion, abridge the freedom of speech, infringe upon the freedom of the press, interfere with the right to peaceably assemble, or prohibit citizens from petitioning for a governmental redress of grievances.
The main way in which the separation of powers guards against tyranny is by making it impossible for any single branch to become too powerful, since each branch "checks and balances" the others out when it comes to making and enforcing legislation.
The US were splitting? The Declaration of Independence