Washington — All over the United States they are packing up to return to Washington, where Congress resumes Monday. As they have for nearly two centuries, legislators bring to the executive the views of distant constituents. And once again international events - this time in the Soviet Union, Lebanon, and Latin America - cut across domestic affairs in America's unique system of divided government.
As Congress returns, the US Marines are suffering casualties in Lebanon, American warships watch continual fighting in Central America, and the nation is outraged by the Soviet's downing of an unarmed South Korean airliner. Congress and White House must work out common responses.
And in the background are practical issues. Where's the money coming from to battle the budget deficit? The nation must either raise taxes, cut expenditures, or face a continuing huge shortfall of at least $200 billion for years to come.
The returning Congress knows already that it would be easier to get a consensus for denouncing the Soviets than for putting its financial house in order. The forthcoming period following the five-week summer vacation could be the last productive period of Congress until after the 1984 elections.
John E. Chapoton, assistant Treasury secretary for tax policy, said this week that he expects no major revenue-raising measures this autumn. Congress approved a fiscal 1984 budget blueprint in June, but House and Senate have not formulated tax increases and spending cuts. Congress sometimes performs a shadow dance during this interval in the budget process. House and Senate committees theoretically approved cuts in federal spending of $12.3 billion over the next three fiscal years, and tax increases of $73 billion. But they have not implemented them.
Congress returns to Washington agitated by world affairs. A conservative minority criticizes the President for not taking stronger sanctions against the USSR in his televised address. But a majority of Congress and apparently the country approves of the tone he has adopted so far.
A more specific question is the role of US Marines in the Middle East. Congress enacted a post-Vietnam statute, the War Powers Act, giving itself a veto over dispatch of US troops abroad. Are the marines participating in a war? The phrase adopted is ''where imminent involvement in hostilities is clearly indicated by the circumstances.''
Should President Reagan agree that ''hostilities'' are involved, he could keep US forces in Lebanon for a maximum of 90 more days, unless Congress specifically extends the period. Some observers believe a sudden withdrawal of US troops at this point would be calamitous.
Other volatile political issues face Congress as it returns for its final preelection session. There are taxes, defense spending, continued aid to Central America, immigration reform, and such varied issues as medicare benefit cuts, a bill to aid the unemployed, school prayer, export controls, health insurance for the unemployed, and natural gas decontrol. Drought-struck farm areas are requesting federal aid.
Congress is aided in one respect: The economy seems to be improving - inflation is down and unemployment is declining.
New claims for state unemployment benefits decreased to 414,000 during the last week in August, according to the US Labor Department, reversing a three-week upward push. Today the stock market is near an all-time high. And the national rate for insured unemployment - an economic signal measuring the portion of the 86.2 million Americans covered by unemployment insurance who are receiving checks - is down to 3.2 percent.
A returning Congress performs two functions - passing laws, and registering the mood of the public. In the latter, the indignation against Moscow may find political expression. Reagan is under attack from activist conservatives who want stronger sanctions against the Soviets.
Lost on the missing airliner was well-liked Rep. Larry McDonald (R) of Ga., for whom memorial services are being held here. Spokesmen for Heritage Foundation, a conservative activist group, say that even though the President has pursued the most conservative foreign policy in a quarter century, he must be ''bolder'' in anti-Soviet actions.