A class approach that puts aside populist criteria is necessary, and this is done on a scientific basis, using the Marxist method of analysing reality, considering the degree of development of capitalism, the process of concentration and centralization in the imperialist phase, emphasizing what is general, without neglecting the peculiarities, and avoiding to place the part above the all. Marxist doctrine establishes the mutual connection between the phenomena of nature and society rather than analyse them in isolation. As V.S. Molodtsov noted "to deny the interdependence of phenomena goes against the possibility of knowledge as a single whole, as opposed to metaphysics Marxism-Leninism developed a truly scientific method of knowledge and transformation of reality. This method requires, first of all, considering all the phenomena of nature and society in mutual connection and interdependence" . These features of Marxist-Leninist analysis are not always followed and dogmatic approaches remain, for example, with regard to the study of imperialism. For example, the relationships of economic dependences are considered fixed, immovable. In addition it neglects an essential quality of imperialism, that Lenin clarified, that it is monopoly capitalism, beating away free competition ; five traits are expressed in Imperialism, the Highest Stage of Capitalism, and they only cling to one, dodging other traits of critical importance. This leads to distortions in the analysis of contemporary interstate unions and the anti-imperialist struggle itself, strictly limiting it to the conception of weak countries versus foreign powers, or economic subordination relations, without considering that capital is developing and there are constant changes, and interdependence phenomena.
Since the beginning of the North American Free Trade Agreement (Canada, USA , Mexico) in 1994, interstate unions are being promoted in America, bilateral, multilateral and even those of continental character, with economic, trade, customs, immigration, regional integration, police and military collaboration.
Latin America is not an exclusive "backyard " of US monopolies, though its economic and political interests are still dominant, there is an increasingly growing presence of capitals from the European Union, China, and even the coordinated presence of monopolies of South America, and monopolies of each the countries involved, which are benefitted and who will occupy key places in the economic areas in which they participate.
Approaches on the class character of these interstate unions are plagued by confusion, because perceptions are mechanically supported by previous elaborations, dogmatically, as corresponding to a different time of development of capitalism rather that in its imperialist stage, and even to historical analogies such as colonial domination. This leads to ambiguity in strategic development by several communist and workers' parties, and to the marsh in the class struggle, tasks and allies are mistaken, and promoting class collaboration, ideological misrepresentation, postponing the historic goal that was already mapped out in 1848 in the program for the communists which Marx and Engels wrote.
A first issue, is the way the Leninist theory of imperialism is assumed. Reductively it is focused as a relation of domination, and not the highest and final stage of capitalism, as monopoly capitalism. Imperialism is thus identified with "Yankee imperialism", as a new colonial power, and maintains that the first task of the Communists is to fight for national independence, a task in which a spectrum of cross-class alliances is designed and the bourgeoisie is divided between "national" and "pro-imperialist"; by anti-imperialist sectors they mean anti-American, not necessarily antimonopoly because that would be involving many "national" monopolies, with which opposition platforms are forged against “foreign” monopolies. It is clear to the Communists, that regardless of nationality, whether they hold a higher or lower place, any monopoly is an essential component of the international imperialist system.
The main conclusion of this misperception is that Latin American countries are dependent, neo-colonies of American imperialism, and this conclusion is signed by a significant number of communist and labour parties of the region, and shared by reformist, opportunistic, and even political expressions of the bourgeoisie, not only at national scale but regional and seeking a continental character, plus it is no coincidence that these formations  have correspondence with projects or mechanisms of some interstate unions, claiming its alternative nature to the American imperialist centre.
It is assumed that the dominant role of the US is static, without considering the inter-imperialist contradictions and intense battle between sharks to occupy the top of the pyramid. True, today in America the monopolies from US are dominant, but they are not as much as 50, 25 or even 10 years ago, because every time they are losing ground to competitors on the rise of other nationalities. Leninist law of uneven development is checked.
When influencing the strategy and tactics, the opportunist character that contains class struggle manifests itself for it sections capital, considering that the national capital must be protected from abroad and leads to loss of class independence of the workers, placing them at the tail of the bourgeoisie.
Let us take the case of NAFTA, against which the Communists have been fighting since 1994, and even before, when it was a project proposed by the government of George Bush. Overall popular class forces, including us , subscribed that Mexico being a dependent country the free trade area meant that Mexico went from being a semi colony into a process of direct annexation by the United States. The struggle perspective stood with the flag of national independence and sovereignty and conceived a broad front with part of the bourgeoisie of the country. If you see the resolutions, declarations issued by PCM then you will find that we had more concern for the future of the industrial manufacturing, textiles, agriculture, small industry, bourgeois facing foreseeable ruin, and you will notice very little reference to the situation of Mexican, Canadian, American and migrant working class. More than two decades later the assessment that history provides allows us to confirm that this approach was wrong, because not only the American monopolies made huge profits, but also Canadian and Mexican monopolies, which strengthened and absorbed the weaker ones in the USA, in the field of telephony, America Movil, and in the mining branch, Industrial Minera Mexico, both dominant Mexican monopolies that plunder, export capital to and exploit workers of the in the US and in Latin America, and have a multifaceted character as they have expanded their investments from telephony to the press, and in general communication services, food, pharmaceuticals, etc. In the case of Industrial Minera Mexico it absorbed several monopolies in the mining and metal-mechanical branch in the US, Peru and Chile. Other instructive examples are the monopoly of the Mexican Bimbo, the food industry, which already dominates the sector in Spain and ventures into China; Construction monopoly ICA, in competition with Brazilian Odebrecht dispute monopoly control of the sector in building roads, bridges and infrastructure; a sobering example is the state monopoly Pemex also locks in that direction, it expanded its line of control in ports and shipyards in Spain. They are not exceptions, you could list other, and check that regardless of nationality monopolies increased their profits, advanced concentrating and centralizing in their field and expanding to others, likewise workers, regardless of nationality, are exploited, impoverished, and are affected by the measures taken by the interstate unions - in this case the NAFTA, to affect their labour rights, reducing them to ashes, devaluing the work and sharpening the capital / labour contradiction, in addition to other measures such as privatization and cutting public sectors of education, health, etc. But not only in the case of NAFTA, Plan Puebla-Panama, bilateral treaties, tried and failed in the FTAA, but also in agreements with the EU, and even in the "alternative" called as MERCOSUR, UNASUR and ALBA, where monopolies of these countries have consolidated as dominant in important branches of agriculture, construction, energy, and also concatenated with blocks, which in the inter dispute with the US, as the case of the BRICS, consider them strategic partners climbing the imperialist pyramid.
Is it correct to speak of Mexico as a dependent and semicolonial country when it ranks 11th in the gross world product? When monopolies are consolidated after a long process of concentration and centralization? According to our findings, set out in the program adopted by the V Congress of the PCM, Mexico is a country of average development in which capitalist relations are fully consolidated, intermediate in the imperialist pyramid, with interdependent relationships that ensure the development of monopolies.
As the Communist Party of Greece states: "History has shown that monopoly as a result of the concentration of capital, as a fundamental law of the present stage of capitalism is a general trend worldwide and can coexist with forms of pre-capitalist economy and property."  That is, in Mexico there are characteristics of economic backwardness, though it is not dominant, as is usually intense and growing capitalist development; there are relationships of dependence and interdependence, stronger with the US economy, and growing with the European Union. We reiterate, there are very strong, dominant Mexican monopolies.
We are convinced of the fight against interstate unions, because these are unfavourable to the people and the working class, and that it has to start from a rigorous class analysis, otherwise, if wrong analyses and perceptions prevail, a wrong strategy will lead to the delay of antimonopoly, anti-capitalist and anti-imperialist objectives.
Among the ideological components of non-class analysis we find the following:
a) Placing the fundamental contradiction as dependence / independence and erroneously displacing the essence of the era which is capital / labour antagonism.
b) Overideologizing the independence and anti-colonialist struggle of the nineteenth century, looking to extract out poetry of the past, and not from the future.  The action and the program of Hidalgo, Bolivar, Juarez, San Martin, Sucre, etc., corresponding to a particular time, two centuries ago, when the rising bourgeoisie found in favour of their class interests the need to form their States freeing them from the colonial domination of the Spanish crown, moving immediately to establish domination of the bourgeois class over the exploited and oppressed. Recognizing the revolutionary-democratic struggles and characterizing these as progressive in its time, is downright insufficient wanting to find in the programs of old the flags that workers must now take up to achieve their emancipation. Concepts such as "Monroeism vs bolivarianism" for example, contribute to conceal that at the time the antagonist is socialism vs. capitalism, and the same applies to projects of "Gran Colombia", etc, etc, today raised by political forces that do not fight against monopolies, but on behalf of those of their respective nationalities.
c) By placing independence as the immediate objective and broad cross-class alliances as the political subject to obtain it, intermediate stages are set, and although those who advocate them may adhere to the socialist-communist goal, they only do so formally for siding with any specific section of the bourgeoisie contributes to the prolongation of capitalist society.
d) Categories such as neoliberalism, globalization, multipolarity, which provide space to the improvement and "humanization" of capitalism, managing it differently, hiding the class conflict in international relations and leading the working class and peoples to take sides in the inter dispute by a block opposite to the US, a more "friendly" one.
e) When considering imperialism as a metropolis, the class struggle in each country is left aside, for the sake of "national unity", to focus on the struggle against foreign domination.