The thing is, the Vietnam war was a continuous process starting in 1945--or earlier, considering that Ho Chi Minh built up the Viet Minh as a patriotic Popular Front movement to combat both Vichy French and Japanese control of Vietnam during WWII. (And to be sure, had been trying his best to oust the French before that; the war was his opportunity to expand his revolutionary movement into a broad patriotic one). The next decade was the French of the postwar Fourth Republic attempting to hold their Indochinese colonies, an attempt that eventually failed. OTL the Americans stepped in to prop up a new South Vietnamese regime the instant the French left; insofar as the war was a "proxy war" against the Soviet/Chinese alliance, the US was already involved even before the French left. First of all we provided the transport of French troops back to Indochina immediately after WWII; toward the end of the French attempts to hold, Eisenhower offered the French the use of nuclear weapons.
On the other side of the "proxy war" equation, that was largely projection by the Americans and other Cold Warriors--the Viet Minh was overwhelmingly a homegrown, do-it-yourself movement, like pretty much all successful Leninist governments that formed after WWII. Indeed both Stalin and Khrushchev, for somewhat different reasons, often found their ideological "allies" to be embarrassing loose cannons and had they followed the directions of Moscow--probably there would be no Communist regimes in Hanoi or indeed in Beijing!
So it is not at all clear what is meant by suggesting the war is delayed by a decade. We could hardly have French Indochina at peace for a decade and then suddenly the Viet Minh start an insurgency out of a blue sky in 1955! OTL they were fighting the returning French the instant they disembarked and indeed lobbying the USA not to help them come back in the first place. The movement was continuous with wartime resistance; putting it on holiday for a decade makes no sense.
Nor is there any sort of space for a decade's respite between the French withdrawal and Americans ramping up serious levels of "aid" to the Saigon government--indeed, without massive US interventions immediately in the mid-1950s, there would have been no Saigon government, no Republic of South Vietnam. If anyone was a "proxy" in this war it was the various shadowy regimes that called themselves this government! Everyone assumed--certainly the American establishment quickly accepted--that had general elections been held across Vietnam as stipulated in the peace treaty under which the French withdrew, Ho Chi Minh would have won hands-down, across the entire country. Therefore it was vital that any regime the Americans propped up would see to it no such elections were held in the South. From the beginning, the government of South Vietnam, such as it was, was utterly a creature of Western intervention--first as an extension and continuation of the French colonial regime, then as a project of American cold warriors. Without Americans already knee-deep in that particular Big Muddy, no South Vietnamese state would even exist.
And the idea that perhaps the Viet Minh would give what was from their point of view essentially just a continuation of the French regime they'd been fighting since 1940 anyway a decade's respite to find its bearings is just silly.
I just don't see any way to insert the sort of interval of a decade in the process your question requires; there was no stasis to maintain, no peace to extend; every year that passed between 1940 and 1975 was a year in which Ho Chi Minh's movement was fighting to, as they saw it, liberate their homeland from foreign rule, and on the other side of it, if the South Vietnamese government ever acquired any sort of legitimacy and credibility, it was toward the end, and after well over a decade of massive American involvement in every aspect of South Vietnamese society.
Had there ever been a stable, established alternative to either foreign rule or the Viet Minh in Vietnam, the whole thing would have been a war of an entirely different nature. Had either the French colonial regime or the American project of building a brand-new puppet state enjoyed a decade's worth of extra success, postponing the equivalent of say 1963 to 1973, the whole dynamic would have been very different--and indeed a different set of options than the best French and American efforts to come up with OTL would have to have been forthcoming as it was not; then again the whole nature of the war would have been completely different. Say the French managed to buy themselves an extra 5 years or so and didn't get routed at Dienbienphu or some equivalent fiasco until 1960 or so--to have held out that long they'd have had to have more success at winning over more Vietnamese to their side, meanwhile on the stages of world politics, instead of a Soviet Union just coming out of Stalin's rule and still fighting the Korean War, alongside a China still apparently joined at the hip to Moscow, presumably at least some of the fragmentation apparent in the Communist Bloc by then OTL would be showing. This might help Americans secure another 5-year extension on their nation-building project in the South, by weakening and isolating the new government in the North.
But if the big, publicly embarrassing interventions the USA had to carry out to protect their investment in Saigon had been postponed a decade, to the early 1970s, they'd be considered in the light of a completely different political landscape. Perhaps if there were no Vietnam War in the 1960s, at least not on a scale like that of OTL, American and international politics would have been more like it was earlier, but this seems unlikely to me. Time and various shifts in the basic structure of things would go on.
A North Vietnam and southern Viet Minh insurgency delayed a decade is essentially a major defeat for those movements, sapping their credibility and depriving them of both domestic and foreign support. It may be interesting to try to imagine WI the war had happened a decade later, but it will require either very intricate and imaginative time-line crafting or sheer ASB fiat to set up that situation! I can't see it; it seems to me that the other sides were trying their best to delay, indeed defeat, Ho Chi Minh as much as they could; if we can imagine more success on their part we might as well imagine the Viet Minh crushed completely. I don't see how to get the same players but delayed a decade.