KARACHI, PAKISTAN.--Poet Rabindranath Tagore wrote many years ago: "I love you my golden Bangla Desh . . . O Mother, during spring the fragrance of your mango groves maddens my heart with delight . . ." This spring there is only the stench of death in the mango groves of East Pakistan/Bangla Desh as many hearts are maddened by massacre.

Firm figures of massacre in East Pakistan, as anywhere, are hard to verify. Some say thousands, others insist on two hundred thousand. Probably 50,000 is a conservative estimate. Numbers of refugees are more obtainable: 650,000 in four Indian states on May 1.

The refugees from East Pakistan insist that those massacred were Bengalis-Moslems, Hindus, Buddhists, Christians living in East Pakistan who were systematically eliminated by the Pakistan Army immediately after March 25 when negotiations for the autonomy of East Pakistan broke down. The West Pakistanis insist those massacred in the "east wing" were Biharis-Moslems originally from Bihar and other Indian states who migrated to East Pakistan after partition but had not yet been absorbed into the Bengali culture.

A visitor to Karachi finds the Pakistan economy going downhill, martial law declared in the West and East, and a Government desperately trying to show a return to normalcy among the 75 million people in East Pakistan. All in Karachi are deeply upset about the massacre of the Biharis, not by the army, but by some members of the autonomy-cum-secessionist Awami League; however, almost all deny any massacre of the Bengalis by the army. West Pakistanis feel the whole situation is an Indian plot-Indian "infiltrators" (soldiers without uniform), Indian ammunition, even Indian (not Pakistan) refugees- aided by a few "antistate elements."

A visitor to Delhi finds an India united as seldom before in recent history with the people pressing Prime Minister Indira Gandhi to recognize Bangla Desh (the independent state of East Bengal) and to give the "freedom fighters" arms. The Indian press emphasizes the massacre of Bengalis. India is obviously taking every political and psychological advantage of the situation, yet so far is acting with great restraint.

In Calcutta and especially at the border, one sees thousands of recent refugees-only one-quarter in camps. Optimistic cabinet ministers of the Bangla Desh Government plead for recognition and arms. Refugees show how West Pakistan has treated East Pakistan as an internal colony for 25 years. They feel their country can no longer remain as part of an integrated, two-wing Pakistan since the events of March 25.

Sheik Mujibur Rahman Awami League won 98 percent of the seats for the National Assembly in East Pakistan during the first national election since independence in 1947. Sheik Mujib campaigned on a six-point platform calling for autonomy, not secession. Apparently the military rulers of Pakistan, aided by the powerful bureaucracy and some industrialists, refused to submit to this major transfer of power. On March 25 they declared martial law, banned the Awami League, arrested Sheik Mujib. and their army began the massacre. Before and after this army action, some elements in East Pakistan apparently indulged in their own massacre in this seldom nonviolent subcontinent.

Why the unconcern about East Pakistan in the U.S., the U.N. and the world? Are Americans unconcerned merely because Moslems are again killing Moslems and, in any case, no white Americans are involved? of because, for once, no ideology appears involved, at least not Communism? of are Americans unconcerned because East Pakistan could easily become a second Vietnam?

Why the unconcern at the U.N.? In an era of norms against genocide, are events in East Pakistan merely an "internal" matter and not a clear violation of the rights of man? Is this situation still "domestic" if it endangers the peace of the world, with Indian and Pakistani armed incursions into each other's territory, not to mention possible intervention by the big powers? Why the unconcern from the nonaligned nations? Does each nation have its own Bangla Desh in its belly? Can no process be devised by the international community face squarely the "autonomy plus" of peoples in the 1970's, so a people, such as the East Bengalis-separated by language, culture, and one thousands miles-can opt for freedom if it is truly a free choice?

Bangla Desh struggles to be born. The green and red flag, with an outline of the country's borders in gold, flies over the headquarters of Pakistan's former deputy high commissioner in Calcutta. And the "freedom fighters" have adopted Tagore's song for their national anthem: "I love you my golden Bangla Desh . . ." Will the U.S., the U.N. and the world do nothing ?