DISCLAIMER: I am not a historian nor a political scientist. I do have a fascination and interest in the Constitution and so I started reading the Federalist Papers and posting my interpretation on my own blog. I thought it might be of some interest here. Your interpretations and thoughts are greatly appreciated in the comments!
Federalist No. 1 here
Federalist No. 2 here
You can find the Federalist Papers in their entirety at The Library of Congress website.
Federalist No. 3 below the fold and previously posted at my LiveJournal
Federalist No. 3 was also written by John Jay and is a continuation of the thoughts in Federalist No. 2.
In this paper, Jay argues for a strong federal government because having such would provide for a strong defense of the young country. Initially, he states that a federal government will provide safety to the nation from threats both external and internal. The remainder of the paper discusses the reasons why this is true for foreign threats.
Jay then states that wars are either just or not:
The number of wars which have happened or will happen in the world will always be found to be in proportion to the number and weight of the causes, whether REAL or PRETENDED, which PROVOKE or INVITE them. If this remark be just, it becomes useful to inquire whether so many JUST causes of war are likely to be given by UNITED AMERICA as by DISUNITED America; for if it should turn out that United America will probably give the fewest, then it will follow that in this respect the Union tends most to preserve the people in a state of peace with other nations.
and states that a united America would give fewer justifications for war thereby providing for a state of peace. Jay then claims that most wars between nations derive from either violations of treaties or direct attacks by the offending nation. He then points out that the young nation already has treaties with 6 nations and trade with at least 3 other nations, 2 of which claimed territory adjacent to the United States (Spain and France). Jay then argues that a federal government would most assure that these treaties would be kept thereby minimizing the likelihood of war.
In the next section, Jay strays a bit from the topic of defense making a statement that a federal government will be made up of more capable men than that of state governments or confederations of governments, although there isn't clear evidence to support this assertion and it seems in 230+ years of experience, this doesn't appear to hold up.
Because when once an efficient national government is established, the best men in the country will not only consent to serve, but also will generally be appointed to manage it; for, although town or country, or other contracted influence, may place men in State assemblies, or senates, or courts of justice, or executive departments, yet more general and extensive reputation for talents and other qualifications will be necessary to recommend men to offices under the national government,--especially as it will have the widest field for choice, and never experience that want of proper persons which is not uncommon in some of the States. Hence, it will result that the administration, the political counsels, and the judicial decisions of the national government will be more wise, systematical, and judicious than those of individual States, and consequently more satisfactory with respect to other nations, as well as more SAFE with respect to us.
In the next sections, Jay states that having a united government will result in more consistent dealings among states and between the United States and other powers. In particular, issues that might provoke one or two states to actions not in the best interest of the nation could be ignored or handled without conflict because the prejudices of a single state will not influence the united government.
But the national government, not being affected by those local circumstances, will neither be induced to commit the wrong themselves, nor want power or inclination to prevent or punish its commission by others.
Moving on to the issue of just causes of war initiated by direct attacks against the nation, Jay argues that a strong federal government again provides for the best defense of the country. Jay uses the Indian wars as an example of how most of these outside attacks are typically a result of attacks against just a state or two. None of them were a result of an issue with the national government. Jay then again refers to the neighbors of Spain and France and how a war between a border state is more likely to result in the absence of a strong federal government.
The final argument Jay makes is essentially that a central federal government will be more likely to have a calm and rational response to these local skirmishes that might involve just one or two states. In a confederation, the argument is that the state(s) most impacted will be more quick to a defense that could result in a wider conflict or war. He closes with the statement that a strong united government is recognized as more legitimate than smaller, weaker states or confederations.
In the year 1685, the state of Genoa having offended Louis XIV., endeavored to appease him. He demanded that they should send their Doge, or chief magistrate, accompanied by four of their senators, to FRANCE, to ask his pardon and receive his terms. They were obliged to submit to it for the sake of peace. Would he on any occasion either have demanded or have received the like humiliation from Spain, or Britain, or any other POWERFUL nation?