America's way forward in world affairs approaches a turning point through a set of national security decisions that demand integrated resolution. Congress and the White House must clearly see and outline for the nation the relationship these decisions have to each other if they are to get any of them right.

The Senate opened ratification hearings yesterday on the Comprehensive Test Ban Treaty to inaugurate this autumn of strategic deliberation. The eventual vote on the global accord to ban nuclear weapons testing will be an authoritative statement of the Senate's vision of America's role abroad for the next decade, and longer.

The test ban treaty vote should not be based on good intentions or on arcane, conflicting technical criteria. The central issue here is as old as the American republic and as political as they come.

That issue is how involved America needs to be in the world to guarantee its own safety. "Little to not at all" seems to be the answer of many of those who favor killing U.S. participation in the test ban and who also want to overturn the Anti-Ballistic Missile (ABM) Treaty with Russia. This in turn would clear the way for construction of a comprehensive U.S. national missile defense system.

These battles bear in spirit on the struggles the Clinton administration is waging this month to get Congress to cough up $1 billion-plus to pay U.S. debts to the United Nations and to stop Congress from slashing U.S. foreign aid to shreds.

Despite appearances, this is not simply isolationism vs. internationalism, Round 223. In the decade since the end of the Cold War these labels have lost most of their meaning. Neither current has been able to establish itself as the dominant force in American politics at century's end.

The end of the Soviet menace was supposed to make America turn inward again. But this sentiment was immediately contradicted by heavy U.S. involvement in building (and profiting from) the new global economy, and in providing leadership to resolve destabilizing ethnic and political crises in Europe and Asia. Americans showed they would not exercise an opt-out clause in world affairs.

Sentiment has also been growing, however, to have America rely almost entirely on its current technological superiority to guarantee American security. Anything that lessens U.S. ability to do what it wants when it wants and how it wants for its own defense is to be rejected, in this view.

A nuclear test ban seems to fall in this category for the Republican majority in the Senate, even though there has been no U.S. nuclear testing since President Bush (!) ordered a moratorium in 1992. Extended by President Clinton, the moratorium has provided evidence that computer simulations can determine the reliability of the major powers' nuclear arsenals without testing.

Politically, Senate rejection of a treaty that President Clinton signed in 1996 with 153 other world leaders would be a blow to the constitutional process at home. And it can only intensify concern abroad about U.S. intentions to go it alone on strategic defense, to the detriment of U.S. allies.

In his last year in office Clinton has begun to bring together a strategy to negotiate new strategic arms reductions with Moscow while seeking a modest updating of the ABM treaty. The goal is to end ABM restrictions that interfere with deploying the first phase of a national missile defense big and sophisticated enough to keep atomic rockets launched by rogue regimes from hitting the 50 states.

The administration hopes to get Russian acquiescence for these changes. But Washington would also eventually need the cooperation of Britain and Denmark to upgrade existing long-range radar stations in Yorkshire and Thule, Greenland, for a missile system effective against Middle Eastern rogue states. Washington needs broad political backing from its European partners as well as it moves forward on changing the framework of strategic defense abroad.

Voting down a test ban treaty already ratified by Britain and France would work against achieving public support in Europe for these U.S. objectives. So will new threats to junk the ABM treaty if the Russians do not yield immediately to U.S. demands.

The administration's efforts in this area are late and timid. But they deserve an opportunity to succeed or fail, and not to be undermined at the starting gate by a hasty Senate vote on nuclear testing held on partisan lines.

As leaders on both sides of the aisle have suggested in recent days, the future is too serious a subject to be determined in the haste triggered by Senate Majority Leader Trent Lott's abrupt scheduling of a vote for Oct. 12. More time, and a serious effort to fit this vote into a broader picture of America's responsibilities and opportunities abroad, are needed.