Federalist No. 20 sees Hamilton and Madison continue to address the ongoing issue of the insufficiency of the present confederation to preserve the union.

In this essay, they discuss the United Netherlands, a confederacy of republics, or rather of aristocracies of a very remarkable texture that confirm all the lessons derived so far. Their review of the celebrated Belgic confederacy finds that while, on paper, everything sounds like the confederacy should be strong, in reality, there is imbecility in the government; discord among the provinces; foreign influence and indignities; a precarious existence in peace, and peculiar calamities from war because it is not a even a true confederacy of republics, but a confederacy of aristocracies that ultimately answers to the stadtholder, an executive magistrate who is also a hereditary prince.

Then they discuss the union of Utrecht, which also reposes an authority in the States-General, seemingly sufficient to secure harmony, but the jealousy in each province renders the practice very different from the theory.

From here they end the piece with a discussion of the province of Holland, the the wealth and influence that allow her to furnish quotas, without waiting for other provinces in the union, and then obtain reimbursements from others by frequent deputations, sometimes at the point of the bayonet. Furthermore, it was often compelled to overleap its constitutional bounds. This demonstrates that a weak constitution must necessarily terminate in dissolution, for want of proper powers, or the usurpation of powers requisite for the public safety.

But regardless of your view, the reality is that, in Holland, and the other provinces in the weak union to which it belongs, the unhappy people seem to be now suffering from popular convulsions, from dissensions among the states, and from the actual invasion of foreign arms, the crisis of their destiny.

That’s why Hamilton and Madison make no apology for dwelling so long on the contemplation of the federal precedents. Experience is the oracle of truth; and where its responses are unequivocal, they ought to be conclusive and sacred. The important truth, which it unequivocally pronounces in the present case, is that a sovereignty over sovereigns, a government over governments, a legislation for communities, as contradistinguished from individuals, as it is a solecism in theory, so in practice it is subversive of the order and ends of civil polity, by substituting VIOLENCE in place of LAW, or the destructive COERCION
of the SWORD in place of the mild and salutary COERCION of the MAGISTRACY. That’s why one union, one nation, is required.

In Federalist No. 19, Hamilton and Madison continue to address the ongoing issue of the insufficiency of the present confederation to preserve the union.

Analyzing the history of Germany, they note that if the nation happens, on any emergency, to be more united by the necessity of self-defense, its situation is still deplorable. This is because military preparations must be preceded by so many tedious discussions, arising from the jealousies, pride, separate views,
and clashing pretensions of sovereign bodies, that before the diet can settle the arrangements, the enemy are in the field; and
before the federal troops are ready to take it, are retiring into winter quarters.

Then, analyzing the history of Donawerth in Swabia, and a period in the thirty years’ war in particular in which friction developed between the Lutheran majority and the Catholic minority when the Duke of Bavaria decided rest control from the Abb de St. Croix, they note that the city was in part of a feeble and precarious Union that we must avoid. The only reason the region did not fall into pieces entirely was that the members were week, and willing to accept the vast weight and influence of the emperor. But the reality was that it was a feeble and precarious Union with a repellant quality, incident to the nature of sovereignty that only served to prevent any reform whatever.

Furthermore, analyzing the Swiss cantons, which scarcely amount to a confederacy, which have no common treasury; no common troops even in war; no common coin; no common judicatory; nor any other
common mark of sovereignty they find that they are kept together by the peculiarity of their topographical position; by their individual weakness and insignificancy; by the fear of powerful neighbours; by the few sources of contention among a people
of such simple and homogeneous manners; by their joint interest in their dependent possessions … and by the necessity of some regular and permanent provision for accommodating disputes among the cantons.. But if the dispute cannot be resolved by a tribunal of impartial parties, or one or more cantons do not adhere to the definitive sentence that the impartial tribunal devises, then under the treaty of 1683, the Duke of Savoy, can interpose as mediator in disputes between the cantons, and to employ force, if necessary, against the contumacious party. The lesson is clear – whatever efficacy the union may have had in ordinary cases, it appears that the moment
a cause of difference sprang up, capable of trying its strength, it failed.

In other words, history has shown us again and again that weak confederacies don’t last. A strong union is essential.