PARIS -- April 30, 1975, was a great day for my country and for me. I was in the first tank that broke into the grounds of the Presidential Palace in Saigon. Though I was a correspondent for the North Vietnamese Army newspaper, I was the senior officer present that day, so I accepted the formal surrender from General Duong Van Minh, known as ''Big Minh,'' the last head of the South Vietnamese government.
What a day! Like many of my comrades, I had fought for more than 30 years - first against France, later against the United States. This was a moment of joy: A country once divided was reunited. Friends and relatives once separated rediscovered one another. There were no more foreign troops - no more Japanese, British, Hindu, Chinese, French, American, South Korean, Australian, New Zealander, Thai - on the soil of the fatherland.
Now there would be reconciliation. That April morning I extended my hand to Minh, inviting him and his aides to join in healing the wounds of war.
But party leaders in Hanoi had other plans. Their dogmatic adherence to Marxism set up a decade of horror, a period in which no reconciliation was possible.
Everywhere prisons were enlarged. Some 200,000 former officers and civil servants of the puppet regime were incarcerated. Collectivization, Stalinist style, was quickly imposed on the South. Throughout the Mekong Delta, private ownership and private businesses were curbed, eliminated, or confiscated, provoking a wind of panic and driving the middle class into emigration.
For the people of the South, it was slow death. It was slow death for me, too. I could see the promises being broken, the slide into repression and suffering. The economy fell apart. Famine appeared everywhere. Inflation was rising, peaking at 800 percent in 1980. The Vietnamese invasion and occupation of Cambodia and a border war against our former Chinese allies in the north sapped resources.
Amid poverty and persecution, millions of people braved the high seas and coastal pirates to leave the country after first paying the liberators in gold to look the other way.
There was no reconciliation during that terrible decade. But through it all, I stayed with the party. I was part of the invasion of Cambodia. I thought I could effect change from within, and from 1975 on I made proposals for change. All were rejected.
By 1986, the Communist Party had allowed some liberalization in a policy called ''doi moi,'' meaning renewal. The day-to-day life of the population improved. There was more money circulating; dollars were present everywhere.
New houses were built. But doi moi was not the cure. Party leaders had adopted it in desperation, and when the Soviet Union collapsed in 1991, the party returned to a more conservative approach.
In 1990, before the open door of doi moi slammed shut, I got out. I was sent on an official mission to Paris and obtained permission to stay longer for medical treatment. While there, I published a pamphlet entitled ''Proposal of a Citizen,'' in which I advocated democracy and integration into the new world environment. I had no intention of defecting, but friends told me it was now unsafe for me to return. Soon I was denounced as a traitor in Hanoi and expelled from the party.
I was now an exile. In my country, meanwhile, a cold climate had descended. International overtures became more hesitant. Hanoi today is still most comfortable doing business with Beijing, Pyongyang, and Havana. The party-controlled media are sympathetic to Saddam Hussein and Slobodan Milosevic. This is because the Communist leaders in Vietnam have one fixed idea: self-preservation.
Under doi moi, everything is theoretically possible - except any challenge to the one-party political system and the exclusive leadership role of the Communist Party. The man at the top, General Le Kha Phieu, the party's general secretary, is absolutely faithful to the inner core of the party. He follows doctrine to the letter, relentlessly and shamelessly parrots party mottos and slogans. He is a party man in a one-party state.
But the outside world is knocking. The World Bank and the International Monetary Fund are putting pressure on Vietnam to reform the financial system and thin out state ownership of business. If the country wants foreign investors, it must make drastic changes.
A quarter of a century has gone by since the end of the war, since that glorious morning of victory. Vietnam today is one of the poorest countries in the world. Per capita income is $320 a year. That is one-third the level of the Philippines, one-sixth of Thailand, one-36th of Taiwan.
Ten years of exile have now gone by for me. The BBC and other foreign media broadcast my voice home on a regular basis. I can talk to friends and relatives in Vietnam by phone, fax, and e-mail. But my wife, my daughter, and two granddaughters remain in the country. I cannot yet go back, and we miss each other dearly.
How long can old-fashioned communists persist in this age of open markets and free-flowing information? My best bet is that they will make some reforms - but very little, just enough to maintain international aid, to gain time before a new, younger generation, more active, more efficient, more vigorous, takes over to bring about decisive changes.
It is too late for my generation, the generation of war, of victory, and betrayal. We won. We also lost.
Bui Tin is a former reserve colonel in the Vietnamese Army and former deputy editor in c hief of Nhan Dan, the Vietnamese Communist Party newspaper. He lives in exile in Paris.
