John B. Anderson, in a document designed to kick off his fall campaign, issued a national unity platform yesterday charging that "our political leaders and political parties have failed the nation" for the last 20 years.

The platform, more than 300 pages long, pictures the United States as a country in peril, "stumbling, uncertain of our purpose, unsure of our strengths, preoccupied with our differences.'"

President Carter, it charges, has "failed to rally the nation" and its allies, reneged on 1976 campaign commitments and "failed to provide coherent and creditable leadership." It accuses Republican standard bearer Ronald Reagan of "simplicity" and advocating a tax-cut policy that would give "a bonanza to the rich, crumbs to the middle class and nothing at all to the poor."

Anderson's independent presidential candidacy, the platform argues, could kindle a spirit of national self-sacrifice by marshaling "a coalition of the center."

The platform puts Anderson firmly on record as the only major presidential candidate opposing a tax cut for individuals. It also adds a few new wrinkles to his longstanding positions -- calling, for example, for a "Convocation on Federalism" to discuss the growing power of Washington over the states.

Yet from a man who boasts of "the Anderson difference" and has campaigned as the candidate of ideas, the platform is not dramatic.

It integrates a host of already-stated campaign positions with Anderson's 20-year record in Congress and with, in some cases, established policies of recent Republican and Democratic administrations. It pictures Anderson much the same as he has been for years: a fiscal conservative and a social liberal.

As a result, the issuance of the platform may not give his campaign the boost his aides hopes for at the beginning of the fall campaign season. Anderson and his vice president running mate, former Wisconsin governor Patrick J. Lucey, almost admitted as much in a letter of introduction to the document.

"It is a strategy of governance, not a game plan for winning the election," the letter says.

Specifically, the platform advocates:

A national reindustrialization program, including a new Industrial Development Administration, tax incentives for small business and the troubled auto and steel industries, and new subsides for research and development.

An anti-inflation program built around wage-price guidelines agreed to by labor and industry, and tax incentives to encourage compliance with the guidelines.

Massive new federal trust funds to improve urban transportation, clean up oil spills and rebuild cities.

An energy program centered on Anderson's 50-cent-a-gallon gasoline tax, coupled with a 50 percent cut in Social Security taxes.

Opposition to the MX missile program (supported by the Carter administration), support of pay increases for military personnel, and renewed emphasis on conventional military forces and naval power.

An emphasis on the United States' "historic alliance" with Western Europe, and a renewed effort to renegotiate and ratify the second strategic arms limitation treaty with the Soviet Union.

Support for the Equal Rights Amendment and opposition to a constitutional amendment against abortion. The platform does not include a statement supporting federal financing of Medicaid abortions, but aides said that was an oversight.

The platform, which was issued in a short and a long version, ends in both cases with a section titled "How an Independent Can Govern." In it, Anderson argues that "The two parties have not yet formulated a realistic post-New Deal public philosophy."

"Victory by our ticket -- in the teeth of enormous insitutional biases against independents -- would be a dramatic signal that the nation wafts and expects action based on consensus," he adds.

The Anderson campaign maintains that its platform differs from the traditional in that it is more specific, is directed toward solving specific problems and doesn't contradict itself. Anderson pledged to issue a detailed budget analysis of his program within three weeks.

The platform puts Anderson on record in the following areas: Jobs

Like the Democratic platform, Anderson's supports the goals of the Humphrey-Hawkins bill, and pledges the Illinois congressman to a full-employment economy. To relieve high unemployment among young blacks in urban areas, he would reimburse employers for 85 percent of the federal minimum wage -- if these jobless people could not be hired in any other way. Nuclear Power

During most of his 20-year career in Congress, Anderson was a steadfast supporter of the development of nuclear power. But his views have shifted gradually, and the platform states that nuclear power should be assessed in light of its large public subsidies, high cost and the possibility that conservation measures may enable alternative energy sources to be phased in. It says no new construction permits should be issued for nuclear plants until safety recommendation from two commissions that studied the Three Mile Island disaster are implemented. The Economy

Anderson supports the concept of a balanced federal budget in times of prosperity and an unbalanced one in times of economic difficulty. Once a balanced budget is achieved, he supports indexing personal income tax brackets "to prevent inflation from pushing taxpayers into higher brackets." He thinks government spending should be limited to a set percentage of the Gross National Product. He supports efforts toward deregulation of the transportation industry and decontrol of oil and gas prices. He supports reducing oil importing by sharply reducing energy usage.

He pledges "a progressive, year-by-year reduction in inflation," stimulating saving by making the first $750 in interest income exempt from taxes (the current figure is $200), and advocates broad use of tax incentives to spur research and investment in new manufacturing equipment. Health

Anderson opposes a national health insurance program supported by his running mate, Lucey, and by Sen. Edward M. Kennedy, and wants more emphasis on preventive medicine. Education

Anderson supports the new Department of Education, favored by Democrats and opposed by Republicans.He would encourage colleges to diversify into adult and continuing education programs. He would increase bilingual education. He considers reading a civil right, and would "direct the Department of Education to attack the massive problem of functional illiteracy." Agriculture

Anderson supports further reform of inheritance laws to preserve the family farm, as well as efforts to reduce federal regulations on farmers. He encourages the use of gasohol and other alternative energy sources to reduce farm costs. Defense and Foreign Policy

In contrast to both Carter and Reagan, Anderson would shelve the MX missile, but like them he favors a general buildup in conventional defenses. Unlike Reagan, he would aim for strategic "equivalence," not superiority, to the Soviet Union, and he would not throw out the SALT efforts.

Anderson opposes a peacetime draft but emphasizes a need to improve the volunteer Army, recommending a whole kit bag full of increased pay and benefits, bonuses for good performance or reenlistment, better housing and other improvements.

Anderson's administration would "establish a balance of prudent expectations in our relationship with the Soviet Union," resisting Soviet expansion, but also seeking "opportunities for reducing fear, uncertainty and misunderstanding through negotiations."

In discussing the Middle East, Anderson contrasts himself implicitly with the Carter administration, saying, "we will not . . . stop to the temptation to use U.N. votes as a means of interfering with the diplomacy of the peace process. An Anderson administration will not label Israeli settlements as 'illegal' and as 'obstacles to peace.'" He says he would recognize Jerusalem as the capital of Israel and move the U.S. embassy there at the conclusion of the Mideast peacemaking process. Housing

On this issue, Anderson came to his first major parting of the ways with Congress more than a decade ago, when he cast the deciding vote for this Open Housing Act of 1968.

His platform calls for passage of pending legislation to strengthen those existing fair housing provisions. He supports a series of actions designed to solve the housing crisis, such as countercyclical mortgage subsidies to dampen the erratic housing cycle, federal mortgage guarantees and simplification of building regulations. Civil Rights

An Anderson administration would bar discrimination based on sexual orientation and "encourage Congress to extend to the Civil Rights Commission the power to investigate" charges of discrimination against homosexuals.

The platform also mentions support for the interests of native Americans, Alaskan natives, the handicapped and D.C. citizens seeking voting rights. Women

The platform devotes considerable space to this topic, in which it reiterates Anderson's support for ERA, abortion rights, affirmative action, equal pay for equal work, more extensive funding for child care, adjustments in discriminatory tax laws and a range of other services or programs.

The Anderson administration will, it says, "make a systematic effort to identify women for key positions," and will require that government administrators collect data by sex and review the impact of their programs on women, as well as the degree of participation by women in policymaking.