Armed conflict is necessary and rarely justified. For that reason I believe it is important for the United States to favor diplomacy over armed conflict. It is important for the United States to understand and other countries to understand, that countries interior conflicts are not the problem of other nations.
I think that the USA should always use diplomacy as a first resort. I do not think an armed conflict should ever be used unless there is no other choice. Using diplomacy not only helps ensure that the USA is seen as a positive entity in the foreign world, it also helps to avoid the loss of lives of soldiers.
The United States of America should absolutely seek diplomacy over armed conflict. We have the right to be the power that the world believes us to be, and we should take that power and move towards armed conflict. Our military may be decreasing, but it is improving with technology every day.
Whenever the United States participates in an armed conflict, they claim that diplomacy has failed, but what armed conflict always results in is the dominance of the winner. The end goal is imperialism, dominance and occupation over a territory, the control of their resources and a heavy say in the function of their government.
I believe the United States should always seek diplomacy first, because we are a country that is able to do so without significant threat to ourselves. Any country that seeks to deceive us can be fairly quickly seen to be doing so because we have such superior air capabilities and downright spying capabilities. It is not worth the cost in military conflict to choose armed combat over diplomacy, especially when we know what the pressures are on the other country to comply. At different times a country might decide that it is worth their while to comply with diplomatic solutions rather than risk armed conflict themselves, and that is something that should always be pursued, even with patience, rather than engage in a war.