Usually, a national anthem is a representation of unity and harmony within the people. Its purpose is to evoke the country's struggles of the past, culture, beliefs, traditions and history. It is usually played during national festivals and holidays to inspire its citizens to honor their homeland with great joy and pride.
This national anthem by HH Trijang Rinpoche was most likely composed with the purpose to strengthen patriotic feelings of the Tibetan people. There was a report that states that the anthem was presented to the 14th Dalai Lama in the 1960s, after he went into exile. This clearly shows that Trijang Rinpoche cared for preserving one of the most important tradition in the Tibetan culture which is Buddhism. A reminder that with the lost of their country, one should not lose their beliefs. This is what I personally believe. As a composer of this anthem, Trijang Rinpoche is not some lame lama but a highly esteem lama of all times.