According to the preamble, why was the constitution written? to provide power to the states to give power to the federal government to provide a common defense

We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defense, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States. So yes the answer would be to provide a common defense.