What was going on when I was born?

The Sun Belt has begun to rival the North in the level and sophistication of criminal activity, say law-enforcement officials across the South. The growth is marked not only by the influx of drugs, particularly marijuana and cocaine, the officials say, but also by organized car theft, prostitution and pornography rings and complex fraud and money-laundering operations. With it has emerged a new criminal class, which some Southern law officials, for lack of a better term, term the Dixie mafia. The expansion of crime in the Sun Belt was illustrated by the evidence presented in the trial of Charles Voyde Harrelson, who was convicted Tuesday in San Antonio of killing a Federal district judge for $250,000. Mr. Harrelson acknowledged on the witness stand that he got a suitcase and a paper bag of money, about $190,000 in all, from Jamiel (Jimmy) Chagra, a drug dealer. But he denied shooting Judge John H. Wood Jr., saying the money was part of a ''drug scam,'' not a murder plot.

How is it that three conservative Republican Senators can frustrate the will of President Reagan, the leaders of both parties and the overwhelming majority of the entire Congress? The Senators used a filibuster to deal a crippling and perhaps fatal blow to an increase in the Federal gasoline tax sought to finance highway repairs and aid mass transit. By contrast, 48 other Senate Republicans today urged the leadership to do everything it could to revive the measure. Enraged Senate Republican leaders bowed to the filibuster Thursday and withdrew floor consideration of the gasoline tax increase and highway legislation, acknowledging that any delay made passage difficult if not impossible.

The Senate, working around the clock in an attempt to adjourn before Christmas, today adopted a compromise endorsed by President Reagan that would allocate the money to build MX missiles but prevent him from actually spending it until Congress approved. The President sought, and won, a provision that would force Congress to vote on the missile system this spring and not delay the matter indefinitely. On Wednesday the Senate Appropriations Committee passed a similar measure but left out the time limit. Mr. Reagan announced that he would name a bispartisan commission to study how to base the MX before he made new recommendations to Congress. (Page 13.)

Despite two weeks of trying, the Governor and legislative leaders have been unable to reach an agreement on how to close the Metropolitan Transportation Authority's budget deficit and hold off a rise in the transit fares. Early today, the leaders met in Governor Carey's office and decided to take the weekend off to consider the impasse and weigh public opinion. Here are some questions and answers about the situation, based on interviews with participants in the process: Q. What is the problem? The M.T.A. projects deficits in the 1983 calendar year of $187 million in the $2.2 billion budget of the Transit Authority and $117 million in the $900 million budgets of the Long Island Rail Road and the northern commuter rail lines. These deficits have occurred largely because a tax package approved by the Legislature in June 1981 is producing about $300 million less than expected for the M.T.A. When they passed the package, the legislators said it was to hold the subway and bus fares to 75 cents for two years.

As OPEC ministers gather in Vienna to discuss ways to reverse the fall in oil prices, industry experts foresee the possibility of a substantial decline in those prices during the coming year. These predictions of a continuing drop from the basic $34-a-barrel level have sparked fears that major exporting nations such as Mexico and Nigeria might lose so much in sales revenues that they could not repay their large foreign debts. This could place even greater stresses on the already strained international banking system. However, in a spot survey of economists this week, most said a moderate decline - say, $5 or $6 a barrel - would prove so beneficial to world economic recovery that the pluses would far outweigh the minuses.

The Justice Department said today that it would refuse to follow a directive from the House of Representatives to prosecute the head of the Environmental Protection Agency unless it was ordered to do so by a court. House officials said the action showed that the White House was advocating obstruction of justice and setting the stage for a constitutional crisis. The Justice Department filed a suit challenging the House shortly after the contempt citation against the E.P.A. Administrator, Anne M. Gorsuch, was voted Thursday night. Assistant Attorney General J. Paul McGrath, who heads the department's civil division, said today that the House's directive for prosecution would not be followed until that suit, Government of the United States of America v. The House of Representatives of the United States, had been decided.

Mayor Koch has developed plans to lay off at least 3,300 municipal workers and leave about 5,300 other positions unfilled over the next 18 months, city officials said yesterday. The plan is designed to meet the likelihood that state aid will be $300 million less than the Mayor requested. The officials said additional reductions, involving possibly several thousand employees in the Board of Education and the Health and Hospitals Corporation, were likely. The total number of reductions, including the 6,300 announced last month, could reach 18,000 by June 1984, officials said.

The official who has headed the K.G.B. security and intelligence organization for the last seven months, Vitaly V. Fedorchuk, was appointed Minister of Internal Affairs today and was succeeded at the K.G.B. by one of his top deputies, Viktor M. Chebrikov. The shift appeared to be linked to moves by the new Communist Party leader, Yuri V. Andropov, to step up a Kremlin campaign against corruption and crime, two major responsibilities of the Internal Affairs Ministry, which controls the uniformed police. Critics of the ministry have long accused it of laxity in the campaign against corruption, or of being corrupt itself. The move also suggested increasing momentum in Mr. Andropov's drive to oust some of the more lackluster loyalists of his predecessor as party chief, Leonid I. Brezhnev. The departing Minister of Internal Affairs, Gen. Nikolai A. Shchelokov, said by the official announcement to be awaiting ''another appointment,'' was one of Mr. Brezhnev's closest friends and a major beneficiary of his patronage since Mr. Brezhnev brought him to Moscow from an obscure provincial post in 1966.

A United States Air Force F-16 fighter crashed Wednesday on a training flight near Sosan, 60 miles southwest of Seoul, but the pilot ejected safely, United States military authorities announced today.

Secretary of State George P. Shultz said today, at the end of a 12-day tour of Europe, that the United States and its allies were in basic agreement on dealing with the new Soviet leaders from a position of military strength while holding a desire ''to solve problems and work constructively for better relations.'' In a joint news conference at Lancaster House with Foreign Secretary Francis Pym of Britain, Mr. Shultz said it was important not to let ''wishful thinking'' about the changes in the Kremlin leadership weaken the alliance's resolve. He said he had found in his visit to seven countries that there was agreement on the need to ''be realistic in our appraisal of what is taking place in the Soviet Union.'' ''The worst thing that the world can do is to allow wishful thinking to lead you to a failure to realistically appraise what is taking place,'' he said. Noting the continued buildup of Soviet military strength, he said the West ''must be strong'' and ready to defend its values.

The Guatemalan Government said tonight that it would not negotiate with ''terrorists,'' but did not say whether it would permit publication a manifesto demanded by the kidnappers of the daughter of the president of Honduras. The deadline for compliance passed late this evening with no word on the fate of the victim, Judith Xiomara Suazo Estrada, a 33-yearold physician who is a Guatemalan citizen.

Chancellor Helmut Kohl's conservative coalition intentionally lost a confidence vote in Parliament today, opening the way for general elections in three months. ''All the parties represented in the German Bundestag want new elections,'' said Mr. Kohl, defending his unusual recourse to the confidence vote. ''The great majority of our citizens also want new elections.'' The opposition Social Democratic Party voted no to the confidence motion, which carried by 218 votes; 248 Christian Democratic and Free Democratic deputies abstained, while eight coalition deputies, troubled by the maneuver's constitutionality, voted yes for the Chancellor.