First, for the use of the word "nation", I quote 3 extracts :

1) Tribes are usually composed of a number of smaller local communities (e.g., bands, villages, or neighborhoods) and may be aggregated into higher-order clusters, called nations.
As an ideal type, the tribe derives its unity not from a territorial identity but from a sense of extended kinship.
(Encyclopaedia Britannica)

2) … In like manner the plan of government of the Grecian tribes, anterior to civilization, involved the same organic series, with the exception of the last member: First, the gens, a body of consanguinei bearing a common gentile name; second, the phratry, an assemblage of gentes, united for social and religious objects; third, the tribe, an assemblage of gentes of the same lineage organized in phratries; and fourth, a nation, an assemblage of tribes who had coalesced in a gentile society upon one common territory, as the four tribes of the Athenians in Attica, and the three Dorian tribes at Sparta. Coalescence was a higher process than confederating. In the latter case the tribes occupied independent territories. (Lewis Henry Morgan, The Ancient Society, Part II, Chapter II. The Iroquois Gens) ...
... The exclusive possession of a dialect and of a territory has led to the application of the term nation to many Indian tribes, notwithstanding the fewness of the people in each. Tribe and nation, however, are not strict equivalents. A nation does not arise, under gentile institutions, until the tribes united under the same government have coalesced into one people, as the four Athenian tribes coalesced in Attica, three Dorian tribes at Sparta, and three Latin and Sabine tribes at Rome. (In the same, Part II, Chapter IV. The Iroquois Tribes).
... A coalescence of tribes into a nation had not occurred in any case in any part of America. (In the same, The Iroquois Tribes).

3) ... 2. BARBARISM
(b.) MIDDLE STAGE. Begins in the Eastern Hemisphere with domestication of animals; in the Western, with the cultivation, by means of irrigation, of plants for food, and with the use of adobe (sun-dried) bricks and stone for building.
We will begin with the Western Hemisphere, as here this stage was never superseded before the European conquest.
b.) MIDDLE STAGE. Begins in the Eastern Hemisphere with domestication of animals; in the Western, with the cultivation, by means of irrigation, of plants for food, and with the use of adobe (sun-dried) bricks and stone for building.
We will begin with the Western Hemisphere, as here this stage was never superseded before the European conquest.
At the time when they were discovered, the Indians at the lower stage of barbarism (comprising all the tribes living east of the Mississippi) were already practicing some horticulture of maize, and possibly also of gourds, melons, and other garden plants, from which they obtained a very considerable part of their food. They lived in wooden houses in villages protected by palisades. The tribes in the northwest, particularly those in the region of the Columbia River, were still at the upper stage of savagery and acquainted neither with pottery nor with any form of horticulture. The so-called Pueblo Indians of New Mexico, however, and the Mexicans, Central Americans, and Peruvians at the time of their conquest were at the middle stage of barbarism. They lived in houses like fortresses, made of adobe brick or of stone, and cultivated maize and other plants, varying according to locality and climate, in artificially irrigated plots of ground, which supplied their main source of food; some animals even had also been domesticated – the turkey and other birds by the Mexicans, the llama by the Peruvians. They could also work metals, but not iron; hence they were still unable to dispense with stone weapons and tools. The Spanish conquest then cut short any further independent development ...
(F. Engels : The origins of the family, private property and the state)

As for what degree my aspect is a marxist one, I can add that Lenin has written : "The nation is the inevitable outcome of the historical evolution, as the expression of social development in the period of the formation and sway of the bourgeois class".

Second, marxism says that capitalism, as all the things and the phenomena in the world, is a mixture of good and bad, which are inseparably tied, a mixture of contradictions, which can only be solved only through proletarian revolution. Capitalism is good because it develops productive forces, creates the working class, concentrates it and socializes the production. Capitalism is bad, because it exploits and oppresses the working people, causing infinite torment and misery for them, and destroys nature and environment. As is apparent, for the bad aspect of capitalism I completely agree with you. Our difference in opinion is that I see the solution in the future, in the overthrowing of the capitalism and the establishment of the proletarian dictatorship as a means toward the abolishment of the social classes and communism (the classless society) and you see the solution in the past, in the destruction of capitalism and in the returning to, I don’t Know (and suppose, you, also, don’t know), which kind of former type of society.
Third, I do not think that the word we use for the social oraganisation of the indigenous peoples («nation» or «tribe») is of capital significance. I made this remark only from the point of view of scientific accuracy. For an additional reason, because I remarked that in english the use of the word «nation» substitutes, in many circumstances, for the word «people». So, in the english translation of the «Origins of the family etc.» we find the word «nation» whereas Engels uses the word «Volk» = people.
Your insistence in the word «nation», perhaps, is due to your opinion that my refusal in using it, is caused by a pejorative attitude of me toward the indigenous people. This is not correct. We, marxists (and not «marxists», the kind that Marx had in view), we feel like brothers with indigenous people, as we do with all poor people and we call them (not as settlers to indigenous, or white people to coloured people, but as proletarians to proletarians) to be assimilated in the capitalist nations, in order to join us in the common struggle for socialism and communism. We, marxists, appreciate and admire the non-state social organisation of the primitive society and we know that the evolution of capitalism, the overthrow of it, will inevitably end in the classless society which will be the revival, in a superior form of the primitive communism, as L.H.Morgan says «It will be a revival, in a higher form, of the liberty, equality and fraternity of the ancient gentes».
And a last citation from the book of Engels to clear, once and for all, the marxist situation about the social organisation of the «first nations» : «And a wonderful constitution it is, this gentile constitution, in all its childlike simplicity! No soldiers, no gendarmes or police, no nobles, kings, regents, prefects, or judges, no prisons, no lawsuits - and everything takes its orderly course. All quarrels and disputes are settled by the whole of the community affected, by the gens or the tribe, or by the gentes among themselves; only as an extreme and exceptional measure is blood revenge threatened-and our capital punishment is nothing but blood revenge in a civilized form, with all the advantages and drawbacks of civilization. Although there were many more matters to be settled in common than today - the household is maintained by a number of families in common, and is communistic, the land belongs to the tribe, only the small gardens are allotted provisionally to the households - yet there is no need for even a trace of our complicated administrative apparatus with all its ramifications. The decisions are taken by those concerned, and in most cases everything has been already settled by the custom of centuries. There cannot be any poor or needy - the communal household and the gens know their responsibilities towards the old, the sick, and those disabled in war. All are equal and free - the women included. There is no place yet for slaves, nor, as a rule, for the subjugation of other tribes. When, about the year 1651, the Iroquois had conquered the Eries and the "Neutral Nation," they offered to accept them into the confederacy on equal terms; it was only after the defeated tribes had refused that they were driven from their territory. And what men and women such a society breeds is proved by the admiration inspired in all white people who have come into contact with unspoiled Indians, by the personal dignity, uprightness, strength of character, and courage of these barbarians.
We have seen examples of this courage quite recently in Africa. The Zulus a few years ago and the Nubians a few months ago -- both of them tribes in which gentile institutions have not yet died out -- did what no European army can do. Armed only with lances and spears, without firearms, under a hail of bullets from the breech-loaders of the English infantry - acknowledged the best in the world at fighting in close order -- they advanced right up to the bayonets and more than once threw the lines into disorder and even broke them, in spite of the enormous inequality of weapons and in spite of the fact that they have no military service and know nothing of drill. Their powers of endurance and performance are shown by the complaint of the English that a Kaffir travels farther and faster in twenty-four hours than a horse. His smallest muscle stands out hard and firm like whipcord, says an English painter.
That is what men and society were before the division into classes. And when we compare their position with that of the overwhelming majority of civilized men today, an enormous gulf separates the present-day proletarian and small peasant from the free member of the old gentile society.
That is the one side. But we must not forget that this organization was doomed. It did not go beyond the tribe. The confederacy of tribes already marks the beginning of its collapse, as will soon be apparent, and was already apparent in the attempts at subjugation by the Iroquois. Outside the tribe was outside the law. Wherever there was not an explicit treaty of peace, tribe was at war with tribe, and wars were waged with the cruelty which distinguishes man from other animals, and which was only mitigated later by self-interest. The gentile constitution in its best days, as we saw it in America, presupposed an extremely undeveloped state of production and therefore an extremely sparse population over a wide area. Man's attitude to nature was therefore one of almost complete subjection to a strange incomprehensible power, as is reflected in his childish religious conceptions. Man was bounded by his tribe, both in relation to strangers from outside the tribe and to himself; the tribe, the gens, and their institutions were sacred and inviolable, a higher power established by nature, to which the individual subjected himself unconditionally in feeling, thought, and action. However impressive the people of this epoch appear to us, they are completely undifferentiated from one another; as Marx says, they are still attached to the navel string of the primitive community. [5] The power of this primitive community had to be broken, and it was broken. But it was broken by influences which from the very start appear as a degradation, a fall from the simple moral greatness of the old gentile society. The lowest interests -- base greed, brutal appetites, sordid avarice, selfish robbery of the common wealth -- inaugurate the new, civilized, class society. It is by the vilest means -- theft, violence, fraud, treason -- that the old classless gentile society is undermined and overthrown. And the new society itself, during all the two and a half thousand years of its existence, has never been anything else but the development of the small minority at the expense of the great exploited and oppressed majority; today it is so more than ever before.
[5] "Those ancient social organisms of production are, as compared with bourgeois society, extremely simple and transparent. But they are founded either on the immature development of man individually, who has not yet severed the umbilical cord that unified him with his fellow men in a primitive tribal community, or upon direct relations of domination and subjection." -- (Karl Marx, Capital Vol. I, p. 51, New York.) Ed.