Like links on a chain, the United States and South Africa recently have worked out a series of agreements that bind them together more strongly.
While the agreements do not seem significant individually, taken together they show that the two countries are solidifying their ties:
* US and South African officials Thursday signed a consular convention that codifies protections and immunities granted to consular staffs of the two countries.
This step signals a move toward more normal relations between the countries, which have been strained due to South Africa's policy of apartheid (forced racial separation). However, the agreement still must be ratified by each country before taking effect.
* Next week the two countries will bring the number of attaches in each other's capitals to full strength.
President Jimmy Carter pulled a US attache out of Pretoria in 1977 after South African black activist Steven Biko died in police detention. South Africa then quickly expelled two more US attaches - all three had been assigned to defense matters - as well the airplane that Pretoria said the attaches used for spying. The number of South African attaches in Washington was also reduced.
The alleged spy plane will also be returned to use at the US Embassy in Pretoria next week.
* The US has indicated it will try to help South Africa secure about $1 billion in credit from the International Monetary Fund - despite a United Nations resolution that calls on the IMF, a UN agency, not to grant South Africa this financial assistance.
The funds would be used to help finance South Africa's balance of payments deficit, which has grown serious partly because of the decline in the price of gold.
During a debate in the United Nations over the credit application, US delegate Gordon Luce reportedly endorsed the loan partly on the grounds that South Africa was making ''constructive change'' in its racial policies.
Among these changes is a plan to bring Indians and Coloreds into the government.
The Reagan administration has also signaled closer relations in the field of commerce. The US relaxed restrictions on trade with South Africa in areas that critics charge could assist Pretoria's alleged nuclear weapons development program.
All these steps appears to exemplify the Reagan administration's policy of ''constructive engagement'' toward South Africa, which is based on the premise that Pretoria can be better nudged toward reforming its racial policies through friendly encouragement than hostile pressure.
Washington's shift in policy has angered many blacks here, who say it gives the government of South Africa a degree of legitimacy and acceptance by the West that it has been increasingly denied in recent years.