Prior to the arrival of the U.S. troops, if the balance of forces between ourselves and the enemy had been viewed simply in terms of specific, material forces, who would have thought that we were strong and were capable of annihilating the puppet army and overthrowing the puppet regime? Later, when the United States sent in at the same time about 200,000 troops who had modern equipment and relied on the strength of overwhelming firepower and rapid mobility, to carry out a strategic counter offensive during the 1965-1966 dry season, we concluded that the Americans and puppets were not strong but were passive, and continued to press the strategic offensive, launched the Bau Bang-Dau Tieng offensive campaign, gained the initiative on the battlefield, and won many victories. In 1968, when the U.S. troops numbered nearly 500,000, with all kinds of modern weapons except the atomic bomb and with the purchasing of the services of lackey vassal troops in addition to Thieu's army, we could clearly see the enemy's weakness and out strength, and exploited that strength to a high degree in carrying out the general offense and uprising of Tet Mau Than, a unique event in the history of war. During Tet we not only attacked the enemy simultaneously in all urban centers, including the U.S. war headquarters in Saigon, the puppet capital, but also defeated the U.S. limited war strategy and forced the United States to deescalate the war, being peace talks in Paris, and adopt the strategy of "de-Americanizing the war" and then "Vietnamizing the war." We thus smashed the U.S. imperialists' strategic global "flexible response" strategy. The international gendarme became terrified of the role it had taken for itself; and the illusion of the "absolute military superiority of the United States" was shattered.
However, during Tet of 1968 we did not correctly evaluate the specific balance of forces between ourselves and the enemy, did not fully realize that the enemy still had considerable capabilities and that our capabilities were limited, and set requirements that were beyond our actual strength. In other words, we did not base ourselves on scientific calculation or a careful weighing of all factors, but in past on al illusion based on our subjective desires. For that reason, although that decision was wise, ingenious, and timely, and although its implementation was well organized and bold, there was excellent coordination on all battlefields, everyone acted bravely, sacrificed their lives, and there was created a significant strategic turning point in Vietnam and Indochina, we suffered large sacrifices and losses with regard to manpower and materiel, especially cadres at the various echelons, which clearly weakened us. Afterwards, we were not only unable to retain the gains we had made but had to overcome a myriad of difficulties in 1969 and 1970 so that the revolution could stand firm in the storm. Although it is true that the revolutionary path is never a primrose path that always goes upward, and there can never be a victory without sacrifice, in the case of Tet 1968, if we had weighed and considered things meticulously, taken in to consideration the balance of forces of the two sides and set forth correct requirements, out victory would have been even greater, less blood would have been spilled by the cadres, enlisted men, and people, and the future development of the revolution would certainly have been far different. In 1972, after a period of endeavoring to overcome many difficulties make up for the recent losses, and develop our position and strength with an absolute revolutionary spirit on the part of the soldiers and people, out troops participated in winning victories in Kampuchea and Laos. However, not all of our main-force units could return to South Vietnam. In that situation we correctly evaluated the positions and forces of the two sides, destroyed many fortified defense lines of the enemy in Quang Tri, the Central Highlands, and eastern Nam Bo, and created many integrated liberated areas at Dong Ha, Dac To, Tan Canh, Loc Ninh Bu Dop, and northern Tay Ninh then, in coordination with the great "Dien Bien Phu in the air" victory in the North, attained out goal of smashing the American's scheme of negotiating from a position of strength, and forced the Americans to sign in Paris, agreements, which benefited us.
Clearly, in each phase of the revolution and of revolutionary war, the correct evaluation of our strength and that of the enemy, correctly realizing the weaknesses of the enemy and ourselves, and correctly evaluation the balance of forces between the two sides are the most basic conditions for the adoption of correct policies to guide the revolution from one victory to another. Our party's leadership of the Vietnamese revolution to complete victory was also based on an evaluation of the balance of forces between revolution and counterrevolution, not only in our country but in the world, was generally correct, although at times and in places, and in some specific details, mistakes were made. But correctness was dominant and determined victory. In actuality, nothing is completely correct. One should not fear speaking about mistakes, but only fear not realizing or correcting mistakes. But every time the balance of forces between ourselves and the enemy it is possible to be rightist and fear the enemy or to be leftist, subjective and faltering n policies and actions. For that reason, evaluations of the situation and of the balance of forces must be based on lines and policies, collective intelligence and on actual developments.
The signing of the Paris Agreement was the clearest manifestation of the balance of forces on the battlefield at that time. The Americans and puppets also carefully evaluated the balance of forces between the two sides after having contended with us in South Vietnam to avoid losing additional land, and carried out the barbarous, evil scheme of using B52's to bomb Hanoi and Hai Phong, and blockading the North. Only after evaluating their capability and will and those of their advisory were they willing to pick up a pen and sign the agreement, and agree to a number of concessions which did not benefit them. We also carefully weighed the strength of the enemy, their schemes, and the possibility of concluding agreements with many points that benefited us. Thus, the Paris Agreement was signed on the basis of the enemy and ourselves weighing the strength and weaknesses of each other and the balance of forces in the world. By signing the Paris Agreement, the Americans were willing to accept a partial defeat, but that was all.
Source: Tran Van Tra, Vietnam: History of the Bulwark B2 Theatre, Vol. 5: Concluding the 30-Years War (Ho Chi Minh City, 1982, pp. 35-36.) The B2 Theatre was north and northwest of Saigon.
If you want to know more about Tran Van Tra and Tet 1968, consult his chapter in the following book.
Tran Van Tra, "Tet: The 1968 General Offensive and General Uprising," ch. 3, pp.37-65, in The Vietnam War: Vietnamese and American Perspectives, Jayne S. Werner and Luu Doan Huynh, eds. (1993).