Washington — As the American people await the second presidential debate Sunday night, the Reagan administration appears to feel confident that it has a creditable record in the field of foreign policy.
Democratic challenger Walter Mondale and other critics point to the absence of an arms control agreement and to diplomatic deadlocks on many regional problems during the four years of the Reagan presidency. But high administration officials make these points in defending the present diplomatic score card:
* The United States has redressed the balance of power with the Soviet Union and, by putting starch into its defenses, laid the groundwork for meaningful arms-reduction negotiations. The Soviet Union is showing more willingness to improve relations.
* Following a toughened US stance in Central America, including the invasion of Grenada, the guerrillas in El Salvador and the Sandinistas in Nicaragua have shown more disposition to negotiate. Quietly, Washington is now engaged in a serious diplomatic process in the region.
* While US efforts to resolve the dispute over Namibia have yet to bear fruit , progress has been made, including the movement of South Africa's troops closer to the south Angolan border.
* The Far East is in excellent shape, from the US standpoint, with China, Japan, and Association of Southeast Asian Nations members all playing roles and pursuing policies that heighten stability in the region.
* Despite lack of progress on regional conflicts in the Middle East, the US is now in a better position vis-a-vis the Gulf states, in part because it is no longer so dependent on oil from the region.
* The administration is holding the line against trade protectionism.
To each of these points, critics have sharp rejoinders. They argue, first and foremost, that Mr. Reagan is the first recent President not to achieve a nuclear arms control agreement with Moscow, largely because of his inherent dislike of the Soviets and a belief that arms agreements are not vital to the nation's security. They point to setbacks in the peace process in the Middle East, including the loss of more than 250 American lives and the inability to forestall terrorism.
They note, too, failure to come to grips with conflicts in southern Africa and Central America.
Administration officials acknowledge the absence of specific agreements. But their fundamental argument is that after what they see as the erratic, vacillating policies of the Carter presidency and the resulting loss of American credibility in the world, the first order of business was to restore confidence in the United States by reinvigorating the economy and bolstering America's defenses.
''Sometimes people measure foreign policy success by the signing of agreements,'' says a high State Department official. ''But the goal is to have the ability to shape conditions in the world ... because people take you more seriously or believe that you will be effective.''
As the administration analyzes it, the policy of detente launched in the early 1970s was an effort to cope with a new superpower equation. Ten years ago the US, emerging from a tragic involvement in Southeast Asia, struggling with stagflation and diminishing resources, and grappling with Watergate and constitutional questions, was in a period of declining power. The Soviet Union, for its part, was in a more upbeat and expansive phase, seizing opportunities around the world to enhance its position.
Now those roles are seen to be reversed. The Soviet Union is confronted with aggravated economic problems at home and difficulties abroad: The Western alliance did not succomb to Soviet blandishments when new NATO missiles were installed; the third-world countries are disenchanted with Moscow; and Afghanistan is costing the Soviets heavy casualties and is alienating Muslims.
''In geopolitical terms the competition has taken its toll on the Russians,'' says the high official. ''They see their hopes frustrated ... and we're coming back.''
Diplomatic observers who tend to be critical of the Reagan foreign policy acknowledge that projecting a more self-assured image in the world is important. ''There's no doubt Reagan is seen in much of the world as a strong leader who has given America, once more, pride and confidence in itself, and this is welcomed,'' says David Newsome, director of Georgetown University's Institute for the Study of Diplomacy.
But critics also see the United States today as less engaged in the world and less relevant in solving critical problems. In the long term, they argue, this is a dangerous posture, because the explosive elements that make for conflict remain and need to be dealt with.
But the administration takes the view that the US cannot be expected to solve every problem in the world if the parties themselves are not disposed to negotiation and compromise. Secretary of State George Shultz adopted a more passive stance on the issue of Israel's withdrawal from Lebanon, for instance, arguing that the parties themselves had to show willingness to make progress.
On the burning issue of arms control, American officials say that if Reagan is reelected, achieving an accord will depend on whether he is willing to resolve the internal dispute between the Pentagon and the State Department over arms policy.
Factors that will affect his judgment, they say, will be a desire to leave a legacy as a peacemaker and the confidence that now the United States can negotiate from a stronger position.