JFK, in some of his final National Security Directives
regarding Vietnam, ordered that the South Vietnamese navy be trained in commando tactics for the purpose of attacking Northern port and other facilities from the sea.
This was an approach not used very much, instead being replaced by direct US Naval presence in the Tonkin Gulf.
If, instead of our using our own Navy, we had continued to rely more on the SVN naval forces as JFK was directing, would we have had the escalation that led to the Tonkin Gulf Resolution of 1964, that, in turn, led to the massive troop and air escalation?
And, if we could step back and look, we'd see the constant issue of the flanking and outflanking maneuver that the Ho Chi Minh trail through Laos and the attacks and infiltration from Cambodia to the east constituted .We could also then see that a military line running from Ha Tien in the far South, on the Cambodian border and near the coast, also could be prepared to run straight, in an unflank-able manner, up to Qui Nhon on the South Central South Vietnam coast. That would be, militarily speaking, a solid line that could not be infiltrated and outflanked by forces operating via infiltration through Laos and Cambodia.
Again, you are forcing the enemy out of a superior position for that southern portion of South Vietnam below that line from Ha Tien to Qui Nhon, and into a position of having to attack that area frontally, not via infiltration and outflanking.
Your ARVN personnel would not become demoralized in holding such a line, and the enemy, on the other hand, would feel increasing frustration at not being able to outflank it. Meanwhile, the infiltration of the northern Provinces by the outflanking maneuver that is forcing us to undertake the partial evacuation of interested civilians from the northern provinces in Annam to below the Ha Tien-to-Qui Nhon line, could be answered to some extent by commando attacks by the South Vietnam navy against Northern port facilities.
The US Naval presence would then be limited to vessels laying naval mines if an when a certain point in the negotiations in Hue had been reached. As the relatively smaller US forces (compared to OTL) were gradually replaced by Non-Aligned forces such as Indian, Pakistani or other nations' forces in holding the Ha Tien-to-Qui Nhon line, the argument that US hegemony was at work would be less of a devilment for the North in its efforts to avert both Chinese territorial demands and military aggression borne of having supplied a great deal of military equipment, and Soviet political and economic demands borne also of heavy military assistance. This would allow the North a face-saving way to tolerate a US presence in the South that was clearly gradually being replaced by Non-Aligned nation forces.
I've often noted that Hue seemed to be the "natural" capital of Vietnam, in some ways, though perhaps not all. There were, after all, three areas of Vietnam, Tonkin, Annam and Cochin. Hanoi governed Tonkin, Saigon, Cochin, while Hue governed Annam.
With Laos lightly populated and militarily weak, it was going to be vulnerable as a base for NVA infiltration and outflanking maneuvers, making the northern South Vietnam provinces relatively difficult and costly to hold, with many withdrawals and counterattacks with the consequent drain on ARVN and Allied morale.
With a solid military line from Ha Tien to Qui Nhon as the new military objective for Allied forces in the South, the morale could be maintained better and casualties and costs contained much more realistically.
Yet, we must, as in OTL, face the daunting prospect of an evacuation of at least part of the population of the vulnerable Annam population in the northern provinces to below the Ha Tien-to-Qui Nhon line. This is the most difficult aspect of this. It is a major imposition on the population of Annam that the Tonkinese are engaged in such aggression through and against their area. If they are made to realize that they are, long term, going to be facing a line they cannot outflank, in the South from Ha Tien to Qui Nhon, they would be less incentivized to continue infiltration and to sincerely negotiate with a more limited US presence.
Again, recall that North Vietnam was engaged in balancing act, OTL, between Russia, China and the West, essentially trying to play one against the other to try to restrain the risk of Chinese, especially, hegemony.
By giving them less to be apprehensive about pertaining to US ambitions in the area, while simultaneously presenting a solid line area in southern South Vietnam that could not be readily seized, we open the door, for the first time, to genuine opportunities for a neutral Vietnam.
The limited US presence in the extreme South would provide something of a check to the threat of a growing Soviet political and economic control in the Northern and Central areas of Vietnam, Tonkin and the northern provinces of Annam.
At the same time, that limited US presence also allows the North an alternative to only Chinese aid as an alternative to Soviet aide, since the US, in de-escalating and finally ending its ground presence in most of the South, is in a position to work with non-Aligned nations in giving Vietnam new economic and trade options.
Thus, the Soviets are incentivized to be interested in use of port facilities in both the North and the South, as well as a Non-Aligned port at DaNang, without having to engage in military activity to achieve them. At the same time, the NVA are dis encitivized to continue attacks against the extreme South, given that such attacks now take on the quality of costly frontal assaults. With the opposing troops in that extreme South also taking more and more the character of Non-Aligned nation forces rather than US forces, both the political and the military--as well as the economic--incentives are in place for a realistic negotiation for a neutralist Vietnam with a balanced economic and trade situation.
There are pitfalls, as noted, including the need to evacuate some of the population of the northern provinces of Annam for a period of time until the true difference (from OTL) in the situation begins to sink in on the NVA general staff and the economic and trade planners in Hanoi, Peking and Moscow, as well as important Non-Aligned nation partners such as India, Pakistan and Indonesia. Vietnam's sister Indochinese states, Cambodia and Laos, are also incentivized to envision a new more prosperous Indochina as well. Another pitfall is the Right in American politics during the time-frame, as they would be calling for more aggressive military action and an escalation instead of a de-escalation, of the US presence.
In this scenario, it is also hard to get a clear idea of what would have constituted a "maximum" US presence, and how long the US presence would remain as it is phased out by Non-Aligned forces.
One key difference that can be seen, is that the US forces are being replaced, not just by ARVN forces but by Non-Aligned nation forces. Vietnamization is still going on, but in a different context and with more of an emphasis of their being replaced, also, by Non-Aligned forces.
I am attempting to evaluate how long this process would take, but of course it is an ongoing process anyway. By going back to before the big US buildup and so forth, we have the luxury here of being able to make all the right moves, would be the idea!