From the official Protectoral document commissioning General Robert Venables, commander of the troops sent on the Western Design, late 1654, written as dictated by Oliver Cromwell (the fleet being commanded by Admiral William Penn, father of the later founder of Pennsylvania) (State Papers of OC's Secretary of State, John Thurloe, vol 2, pp. 28-9, as quoted by me in my book 'Cromwellian Foreign Policy' pub. Palgrave Macmilan 1995:
1. The choice of islands for the intended invasion, either Hispaniola or Puerto Rico - Jamaica being the second choice by Penn and Venables after their failure to capture Santo Domingo, capital of Hispaniola, and not even mentioned by OC. 'Many Englishmen will come thither from other parts and so become magazines (ie storeage-depots) of men and provisions for carrying on the Design on the Mainland'. Cromwell only intended the milit expedition from England as stage 1 of a grand campaign to move on, helped by the existing English colonists in the Caribbean (mainly on the Bahamas, Bermuda and Barbados at this point) , to invade the mainland of South America, ie modern Venezuela and N Colombia - and in 1655-8 he sent envoys round these colonies and to New England to get as many colonists there as possible to move to the new English base (in fact Jamaica) to back his plan, saying that it was their godly duty to help defeat the 'Papist' Spaniards. He had a rude shock to find that most would not leave their existing homes for a new, hot, and insecure island base with few houses and little agric land ready so they would mostly have to start from scratch again - even the 'Puritan' colonists of New England, who he had great hopes from and sent locally well-known preacher and pro-Cromwellian Vincent Gookin to recruit, did not move except for a few younger men with no or poor homes and jobs plus a few women chafing at parental authority. The, often pro-Royalist and less religious, colonists of the southern N American states (only Maryland and Virginia at this date) and Barbados were even less enthusiastic.
As a result the Cromwellian reliance on having this help for a series of expansionist new colonial outposts in the Caribbean and later the S American mainland flopped badly - and it was unrealistic to expect people in settled homes to uproot themselves, esp when some Spaniards and runaway African 'maroon' ex-slaves on J were still resisting in the hills, ie until 1658. This would have faced OC even if he had lived into the 1660s and had the security at home to keep sending men to the area. The reliance on local settlers help also aided the decision of the Protectoral Council to send a smallish force, with men collected from several regiments not sending full regiments who were used to fighting together - and with Charles II still at large in France and at this date France not having signed peace with the Protectorate to stop their help to the Royalists (they did this in Nov 6155, after the Design) OC could not risk sending out first-rate troops from top regiments. Often the men chosen were ones who their commanders wanted to be rid of, and numbers were later added to for reinforcements and for civilian settlers in the same way ie a bureaucratic policy of 'make up the numbers to carry out our orders and please the govt and hope for the best' (sounds familiar). Prisoners, including Royalists and deported Irish Catholics, and even arrested London prostitutes were sent too as settlers to get rid of them. The whole episode was a typical mixture of an ideological leader who wanted to carry out an 'easy' foreign expedition against an ' ungodly Papist menace', ie the Spanish empire, to stimulate national unity and emulate the legendary 'successes' (magnified by myth) of Drake and Raleigh, plus incompetent and bumbling implementation and a govt lack of understanding of the situation on the ground, least of all of the risk of disease (cf overconfidence in Iraq and Afghanistan in 2000s??). One or two of the Council, led by sensible Yorkshire officer General John Lambert, did warn OC of the risks and the overconfidence in discussions in 1654 (and what the govt would have to face from family and friends of officers and men who died in a badly waged war with no clearly useful purpose) and were ignored. The govt media (pamphlets written by spindoctors) cheerfully presented the resulting war and the situation in Jamaica as far better than it really was, to the point of distortion - nothing new there.
Cromwell also suggested moving on to take Havana in these instructions, section 1: 'it is so considerable that we have thoughts of beginning the attempt on Cuna and still judge it worthy of consideration'. The choice of Santo Domingo was that of Venables and Penn on reaching the Caribbean, probably as it was less populated and had fewer troops and towns to take than Cuba . Their attack on SD was partly foiled due to poor maps, which left out rivers which they had to ford en route to the main town, partly due to lack of martial spirit and determination from troops and officers alike when they found the town prepared to resist, and partly due to poor weapons and inadequate ammunition sent from GB and less than expected in the hands of the local settlers in Barbados to ad to their supplies.
Section 2 of the Instructions makes it clear that the Design was then to move on from taking a major island to Cartagena on the (modern Colombian) mainland - 'aiming chiefly at Cartagena, the seat of the intended Design (ie its main objective), securing some places by the way thereto that the Spaniards might not be to the windward of us'. The plan was to keep the Spanish troops on the S American mainland from attacking the English, by securing the ports East of Cartagena into modern Venezuela - the Easterly winds meant that a seaward attack would be virtually impossible from the West (ie Central America where most Sp troops and ships were) , but would have to come from the less populated and easier to overrun lands to the East (ie around Caracas). Taking this section of coast would stop this happening . The plan was strategically well thought out, and the official docts which I studied for my doctorate show that it probably came from Cromwell's (ex-Royalist) Barbados planter ally, Colonel Thomas Modyford - later governor of Jamaica in the 1660s - and some other locals with knowledge who were in London in 1654 helping Cromwell. These included one of the Winthrops (Stephen) and some New England captains, who knew the local seas - and probably were starting slaving too around this time. So OC did have 'professional' advice - it was luck, poor leadership and over-confidence that wrecked the plan. But it could have a reasonable chance to take Cuba or Puerto Rico or Hispaniola if it had been larger and luckier. (Cuba also nearly fell in 1762, when the British attacked - but by this date jealous and well-connected W Indies sugar planters probably did not want an English Cuba as a rival and would have asked the govt to hand it back in the next treaty with Spain.)
As a note, the Eng govt also explored setting up a colony in Florida in 1655-8 to intercept Sp treasure galleons en route from Havana to Spain and cripple the Sp supply of money to Europe to run their army there - and OC received a Native American chief in London with this in mind. On of the enthusiasts for this was Secretary Thurloe's merchant adventurer brother in law Martin Noell of the East India Company, another was New Englander Vincent Gookin. Another potential 'What if' had the Protectorate lasted longer?
