Consider the plight of small businessman, Fred Rollins. His boss is in New York, needs government approval to vist Milwaukee, speaks English as a second language and the home office is 4,900 miles away. And then there was the Soviet invasion of Afghanistan.

"It probably hurt," Rollins said matter-of-factly the other day at his office on Milwaukee's northwest side.

"Probably" is probably an understatement.For Rollins, the Soviet invasion of Afghanistan must have been a saleman's nightmare.

A cheerful and open man, Rollins is general manager of Belarus Machinery Co., a wholly owned subsidiary of Tractoroexport of Moscow, U.S.S.R., which sells an inexpensive, sturdy, no-frills tractor for the proletariat of American farmers.

So far it's been rough going, but not even the harsh anti-Soviet rhetoric of President Reagan and Secretary of State Alexander M. Haig Jr. has discouraged Rollins.

Belarus is a unique instrument of Soviet economic policy in the United States. While far-flung U.S. multinational companies peddling goods around the world have become commonplace, Soviet multinationals operating in the United States are still rare, struggling and trying every capitalistic trick they can devise.

The Soviets operate 84 such companies, five of which are in the United States. Through them, the Russians hope to earn hard currency for purchasing U.S. grain and other products and to increase their prestige as exporters of finished goods.

Last year, a bad year because of the grain embargo imposed by then-President Carter in response to the invasion trade between the two countries totaled $2 billion, but only $453 million represented U.S. imports of Soviet goods. Most of that was for raw materials, such as ammonia, gold bullion and other metals. Manufactured goods hardly show up in the records.

"Trade is both sides. We should not just buy, we should sell," said Dmitri Monaenkov, president of Belarus.

But the Soviets are doing precious little selling. "Soviet officials are increasingly reluctant to do business here," said William D. Forrester, director of communications for the U.S.-U.S.S.R. Trade and Economic Council. "Licenses are being denied and negotiations are being tabled. The situation [in the United States] is unstable."

Belarus is unusual because it is the only Soviet company in the United States whose sole interest is selling manufactured products. It was formed as a Soviet-owned corporation in Milwaukee in 1977, has an office in New York City, where Monaenkov works, the main office in Milwaukee and a distribution center in Louisiana. Most employees, like Rollins, are Americans.

Other Soviet-owned companies operating in the United States include Sovfracht, a shipping company, and Amtorg, a trading company. The Soviets also would like to begin marketing Lada automobiles, a model based on the Italian Fiat 124, through a U.S.-owned firm, but the idea has not gone very far.

Belarus has been hampered by restrictions denying the Soviet Union status as a favored U.S. trading partner and by the political climate, which in the eyes of Belarus officials is not much different under Reagan then under Carter. The company sells aabout 500,000 tractors in 60 countries annually, Rollins said, but the market here is just "small potatoes."

"It would be arrogant to say we're competing with the Americans," he said.

In the company's best year, 1979, it sold 1,110 tractors and earned a $350,000 profit. Then 1980, immediately after the Afghanistan invasion, also was a bad year generally in the tractor industry, and sales declined to about 600 to 700 a year.

The company's goal is 3 percent of the market in sizes it produces, but to date its share is about 1 percent. Despite Reagan administration antagonism toward the Soviet Union, Belarus officials are encouraged by the end of the U.S. grain embargo and the new agreement to resume trade.

From the outside, the Belarus plant looks like the heartland's normal mixture of patriotism and capitalism. The American flag snaps crisply in the afternoon breeze. Behind the flagpole, on the building wall, is the company symbol, another American flag shaped like a U.S. map, with a stylized tractor superimposed.

Inside, the problems begin. The Soviets simply are not style conscious. Their tractors, which look crude by American standards, may be built for the ages but, without a comfortable seat and air-conditioned cab, do not interest many American farmers.

Rollins and associates have prodded the Soviets to spruce up some of the new models, with noticeable results, and the Soviet farmer still would not recognize the carpeting and other extras added at the Belarus plant here.

Nor would he recognize the color. When the tractors arrive from the Soviet Union, the orange coating looks so shabby that the Americans repaint them completely. Naturally, the new color is a briliant red.

Looks aside, the Belarus tractor has a few things in its favor. It is about 20 percent less expensive than a comparable American model and is highly fuel efficient. Getting parts is no problem; Belarus keeps at least a two-year supply in Milwaukee.

But the tractor is not for everyone. "Our market is not the affluent farmer," Rollins said. "It's the little guy we appeal to."

The company does reasonably well in sections of Wisconsin and Minnesota, Louisiana and east Texas, and Rollins believes there may be opportunities in the South and New England.

"We don't mess with Illinois," Rollins said. "That's rich farmland with prosperous farmers. They don't perceive a need for our tractors."

Another problem, as Rollins put it, is that "some farmers just won't buy a tractor made in Russia. But when you talk about the country of origin, six out of 10 times our dealers can overcome it."

Belarus maintains about 200 dealers, mostly east of the Mississippi, and they use everything from logic to levity to make a sale. "When we first started, we heard a lot of derogatory remarks," said George Strobel of Hartford, Wis., who sells about 12 tractors in a good year. "Our relations with them haven't been the greatest down through the years."

One of his customers is William Sell, 66, who owns 40 acres just north of Hartford. A grizzled man with a white stubble of a beard, Sell and his son bought their Soviet tractor a few years ago and have had only one problem with it.

The politics of the deal do not bother them. "What's the difference?" Gary Sell said. "German, Japanese, Russian. We could get into a fight with any of them."

Like any company trying to make a buck, Belarus offers incentives to dealers. Last summer, the top 10 dealers won a free trip to the Moscow Olympics and a tour of the main factory in the motherland.

Still, Belarus has had only one profitable year since incorporating in 1977 and is still making up losses incurred that first year.

What does the home office in Moscow think of this record?"They understand our situation here," Monaenkov said, "but they would be happy if we sold more."