If you've ever played soccer, American football, or other similar sports with goals on each side of the field, then you probably realized it's much better to keep your offense pressing the defense of the opponent and keeping the game on their side of the court or field. In doing this you have a more likelihood of scoring a goal, and you are better able to prevent attacks on your own goal. Let's go ahead and stop right here, and call this theory; "the best defense is a good offense."
Next, there is something that is uniquely and inherently problematic about always being on the offense. When you are always on the offense you hone your skills on attack strategies, and you aren't very good at defense of strategies. Now then, the reason that we have a federal government is to pool the resources of the states for our common defense; in other words, to protect the American people from a foreign invasions or attack.
Since we are the greatest nation ever created in the history of mankind with the greatest wealth, and therefore currently we have the strongest and most powerful military in the solar system, it makes sense to position that military in such a way to provide for our common defense in such a robust fashion that no one would ever even attempt to think about attacking our goal on the side of the field or in this case on our side of the planet.
Americans don't ever believe that an enemy army might come into their cities or bomb their cities using advanced weaponry, but with our borders so open and unprotected - US citizens would be naïve to assume they are safe. The reality is no country is safe on a planet with humans organizing against your best interests. We have enemies of the United States abroad, which are coming together and uniting against us as their common enemy. Therefore, it is time not only to protect the European continent from their enemies, to protect our allies in Asia, the Middle East, and Africa, but also to protect our own borders.
You see, we have a lot to protect here, and being such a great nation we have a lot to lose. Therefore it is absolutely incomprehensible that the leadership of this great nation does not do more to provide an ironclad defense with every single possible technology known to humans and beyond to protect all we are and all we've built. Anything less than absolute 100% security for this nation is unacceptable. We did not come this far to throw it all away on a wing and a prayer. Yes, we should play on the other side of the field, but we should also have extra men on the field for our defense, because we are the ones making the rules and this is our game to play. We must play to win!