I’d say that your first two suggestions could be implemented, while the last might be difficult. What criteria would you use to say that a country supported terrorism? Should those criteria be universally applied? What if the nation had the ability to do us great damage? For example, say the Chinese were caught red handed (pardon the pun) supplying arms and money to the Nepal insurgents and suppose those insurgents had committed terrorist acts (as they have done). Would you be willing to start a war with China to enforce your terrorism policies?
Forget about rebuilding them afterwards. Leave them in the stone age we put them in. These "conquests" should be about punishment, not rehabilitation.
This was the policy of Imperial Rome, and it worked pretty well. The problem with this strategy today is the much higher cost of regional instability. Let’s imagine that we follow this policy in Iraq. We invade, destroy their infrastructure and then leave. What happens? Now you have millions of Iraqis with no access to food. Some starve, the rest become refugees and journey to their neighbors: Kuwait, Syria, and Saudi Arabia. There mere presence will cause disruption in nations that supply the world with a large chunk of its oil wealth. Furthermore, they might influence the populations to strike at the West, perhaps in the form of oil embargos. Like it or not, such actions could cause major economic problems.
Announce we shall do the same to any country that threatens us again.
This will have consequences as well. Nations that feel threatened by the US are more likely to seek the acquisition of weapons of mass destruction. In addition, such states are more likely to form defensive alliances; they may even combine resources and share technology to develop such weapons more quickly. For example, North Korea could trade Rocket technology for Iranian resources or Pakistani nuclear know-how. What if China or Russia felt threatened by American activity? The United States is strong, but we cannot fight the whole world.
We should also tie all foreign aid monies (everywhere) to their attitude towards us. Any negative word about us and they are cut off.
Remember that Nations are not unitary actors. Nations, even governments, are often made up of competing factions. Let’s imagine that I’m a Muslim fundamentalist with a low level position in the Egyptian government. Wouldn’t it be in my interest to help cut off American foreign aid? After all, it could help bring people over to my side. And if I were successful, wouldn’t I be a step closer to replacing that government with a fundamentalist regime?
When considering foreign policy you have to be very careful. Sometimes actions that seem to be in one’s best interest can cause the very conditions one sought to avoid.
You're making the mistake of assuming that we left millions of iraqis alive.
War is won by destroying the enemy. Either killing all of them or so changing their culture that war is unthinkable (as we did to japan). The problem with changing the culture of islam is that the religion COMMANDS its adherents to lie. So even if they claim to have converted we cannot trust them. They must be destroyed. (Of course they must be given a chance to convert but that doesn't have any effect on the imposition of justice here on Earth)
God Save America (Please)