Here are some Soviet covers which I acquired while in Azerbaijan. It was a great pleasure for me when I saw them, and I grabbed them on the spot because they are exactly my theme: flags, coats of arms, and patriotism.
Of course, patriotism in the USSR, especially in the "satellite" members (a.k.a. all of the member states besides Russia) is not an easy topic as this "patriotism" was imposed on all peoples across the whole soviet realm by the Soviet government and did not really rise from the hearts of the people. What I mean is, in communist societies, national identities were (and still are, read: China and its westernmost provinces) oppressed and everyone is bunched up together to form one homogeneous "identity" that is strictly defined by the state.
Oftentimes, the culture and language of the nation to whom the majority of those in power belong is considered the "standard identity," so to speak. The repercussions of this imposition of culture and ideology are very powerful. For example, in most of the ex-Soviet states today, Russian is still widely spoken and understood. In some societies, such as Kazakhstan, there have been recent campaigns aimed at promoting the national language and reverting to speaking Kazakh once more. Of course, this can only be achieved up to a certain point because the effect that the Russian language has had on the local language is indeed indelible.
For instance, in Azerbaijan most people converse with each other in Azerbaijani, although there are still a few instances when you will ethnic Azeris who grew up in Azerbaijan and yet are very bad or do not even speak in Azerbaijani! However, because the modern world with its modern systems and modern machinery developed when Azerbaijan was under the Soviets, many words, such as "xolodinik" for refrigerator and "propka" for traffic still remain in everyday use. Also, things such as "smetana" (sour cream), "zakanoe" (registered letter), and "mashin" (car) are still alive and kicking in Azerbaijani vocabulary. Of course, there are some instances when translations into the national language are used ( such as "sifaishli" for registered mail), but there are rare - and usually official - occasions.
The imposition of culture and language is certainly not limited to the case of the USSR. While the Spaniards did indeed impose their heritage onto the Filipinos during the 333 years of its reign in the Philippines, at present it is now the Tagalog language and culture which is being imposed on the different peoples who populate the islands that belong to the state. It is because the seat of government is in Manila, where the language spoken is Tagalog, that the national language officially called "Filipino" is basically 90-95% Tagalog. I have a feeling that the same goes for Germany. I live in Bavaria, where they speak Bavarian, which is similar to standard German, but also quite different in many ways. However, the official language on all documents and on the signage here is standard German nonetheless.
This first cover celebrates 50 years of the Turkmen Socialist Republic as well as the 50th anniversary of the Turkmen socialist party.
The theme of this second cover has little to do with communism and it seems that it is celebrating something along the lines of 100 years of song or singing in Estonia.
This one celebrates 50 years of the Moldavian Socialist Republic and the Moldavian socialist party as well.
This cover commemorates 50 years of the "Great October," also known as "Red October." For some reason, it mentioned Tajikistan on it, but I am not quite sure why. Perhaps this issue was commissioned by the Tajik government? The FDC cancellation does indicated Dushanbe, which is the capital of the country.
The following is a set of 6 FDCs of stamps celebrating 50 years of the establishment of the Soviet Union. I particularly like this kind of socialist propaganda material because they try to depict that everything is well in the "nation," and that everyone is enjoying life and everything is productive. I guess it is this twisted sense of reality and this effort to pretend that everything is going as planned that appeals to me most. It is not that I agree with the idealism, it is just that I find it amusing how some people can be blinded by ideas.