When Buchanan, Mason, and Soulé met in Ostend they reached agreement on a Cuba policy. The Pierce expected some kind of secret position paper that would go into the mail and in due course arrive back in Washington for careful consideration. Doubtless steady, cautious Buchanan would keep things from flying off the rails.
Soulé’s theatrics put the notion of secrecy to rest and anybody paying attention to the European diplomatic scene knew the American ministers had something up their sleeve. The Manifesto went public and presented Washington with the unhappy choice of repudiating it and paying both a domestic political price and suffering international humiliation over letting its ministers engage in wildcat diplomacy or owning up and endorsing the document and so embracing a kind of secretive chicanery from which the administration had lately disassociated itself by suppressing Quitman’s expedition.
But what did it say? It opened with a very conventional sort of diplomatic language. Anybody would ask what vital interests prompted such a deep concern for Cuba on the part of the United States, so the Manifesto explained that
Cuba is as necessary to the North American republic as any of its present members, and that it belongs naturally to that great family of states of which the Union is the providential nursery.
From its locality it commands the mouth of the Mississippi and the immense and annually increasing trade which must seek this avenue to the ocean.
The natural and main outlet to the products of this entire population, the highway of their direct intercourse with the Atlantic and Pacific states, can never be secure, but must ever be endangered whilst Cuba is a dependency of a distant power in whose possession it had proved to be a source of constant annoyance and embarrassment to their interests.
The Black Warrior affair might subside, but what about future shipping? Any captain-general down the road could seize another ship, or a dozen. In the interests of fairness, one must note that the ship in question only touched at Cuba and plied what amounted to a domestic trade. It stretches the idea of national sovereignty to extend it over foreign ports but the idea has at least a grain or two of plausibility.
But another concern made acquisition urgent and its delay “exceedingly dangerous to the United States.”
The system of immigration and labor, lately organized within its limits, and the tyranny and oppression which characterize its immediate rulers, threaten an insurrection at every moment which may result in direful consequences to the American people.
Cuba has thus become to us an unceasing danger, and a permanent cause of anxiety and alarm.
The skilled hand of a diplomat shows through. One could ready that passage quickly and miss that it refers to slave revolts. A successful slave revolt would give American slaves the benefit of a good example. This genuinely terrified many of Southerners. But Europe should assent for humanitarian reasons as well: Cuba supported the African slave trade. (A Louisianan like Soulé ought to know, as his state housed many who wanted that trade reopened and smuggled slaves in illicitly from Cuba.) The Manifesto further held that the Cubans lived under a brutal, arbitrary tyranny, words sure to endear their authors with Madrid.
Then came carrots for the Spanish. With the money the United States would hand over, Spain could catch up to France and link itself to the French rail network, facilitating trade and the attendant revenues from the Channel to Gibraltar and have cash left over to pay off bonds that sold at one-third their face value even on the Spanish market. A chance to pay off that debt, especially the part of it owed to British speculators who had a history of calling on their nation to serve as a collections agency, might never come again.
So, according to Buchanan, Mason, and Soulé, the Spanish ought to sell immediately. Only a fool would refuse. So far as that goes, the Manifesto did not much transgress the usual line of bellicose imperialistic diplomacy. In an era when the Great Powers fairly routinely invaded and seized for themselves entire countries, Cuba stood out mainly in that a Great Power already held it.
If the Manifesto stopped there, probably no one would have much cared. It might push hard sell a bit too much, but it ultimately amounted to a statement about a legal purchase.