Washington — Wars and rumors of wars. As the National Conference of Catholic Bishops continues to meet today to consider its controversial pastoral letter on the threat of war, the world finds itself increasingly engaged in violent military conflict.
Today, there are some 40 major and minor wars involving 45 of the world's 164 nations, which was reflected in a recent warning by United Nations Secretary-General Javier Perez de Cuellar that the world is ''perilously close to a new international anarchy.''
''Over the past three years, conflict, violence, and international tensions have increased in nearly every region of the world,'' states a recent study by the Center for Defense Information. Six new wars have started since the last such report in 1979, while only two have ended.
''Even more striking is the escalation of violence in continuing struggles,'' says this global survey of military engagement around the world. Of 35 continuing conflicts, 25 have seen increased fighting over the past three years, 7 show no change, and only 3 show notably lower levels of conflict.
''The Challenge to Peace'' (the title of the bishops' pastoral letter) coincides with other calls for reforms of international institutions and with warnings such as President Reagan's that the United States faces growing threats to its security and must lean harder on its adversaries. It also comes as the US Congress continues to debate the highly political nuclear freeze issue, and as experts urge restructuring of US forces to deter and, if necessary, respond to the forms that future conflict is likely to take.
''Most of these wars are not 'good-guy, bad-guy' situations,'' says retired Rear Adm. Eugene Carroll, deputy director of the Center for Defense Information. ''They often involve complex combinations of economic, political, territorial, religious, and ethnic factors. The main ideological thread woven through almost all the diverse conflicts is nationalism, not communism vs. democracy.''
Yet in four of the five ''conventional'' wars (the exception is Iran-Iraq) currently being fought, the US supports one side and the Soviet Union backs the other. And in nearly three-fourths of the 40 military conflicts, superpower support of one or both sides is evident. Conventional wars involve conflict between nations, as opposed to internal fighting.
While public attention tends to focus on places like Lebanon or El Salvador, as many as 4.5 million soldiers are now engaged in combat around the world. Most of these involve revolutionary or separatist guerrilla conflicts.
The US Army recently commissioned the Center for Strategic and International Studies at Georgetown University to project the Army's strategic needs through the end of the century. This prestigious study group (which included James R. Schlesinger and Zbigniew Brzezinski) warned of ''an age where conflict can be manifest in a wide variety of ways.''
In looking ahead to the year 2000, the group assumed that general nuclear war or catastrophic breakdown of the world's economic order would not occur. But it warned that ''in the turbulent world of the 1990s,'' challenges to US international security interests will grow and ''the nature of America's world leadership role will be tested repeatedly.''
''Low-intensity conflict,'' psychological warfare, high-technology terrorism, urban guerrilla warfare, and more ''conventional'' proxy wars - inspired or exploited by the Soviet Union - will be the likely principal challenges, the Georgetown University group reported. Mobility, flexibility, smaller units, lighter and simpler weapons, and peacetime conscription will be necessary to meet these challenges, the group suggests.
In its report ''A World at War - 1983,'' the Center for Defense Information points to the following as evidence that just since the first of the year there has been a ''growing pace of conflict around the world'': Iran's major offensive against Iraq; attacks on Muslim immigrants in India; increased fighting between government troops and guerrillas in the Philippines; major offensives by rebels in El Salvador; increased fighting between SWAPO guerrillas and South African troops in Namibia; advances by the 180,000 Vietnamese forces in Kampuchea; and continued deployment of Soviet missiles and personnel to Syria.
It is generally assumed that major superpower confrontation, if not avoided, would be sparked by this kind of regional or local conflict. While the Roman Catholic bishops in Chicago wrestle with such issues as the ''just war'' and whether or not the use of nuclear weapons can ever be justified (they agree to the first and say no to the second), world conflict continues to grow.