THERE are many troubling aspects to the current Bosnian venture, but the most disappointing has been President Clinton's failure to guide the nation back toward sound constitutional practice. By insisting that he did not need congressional approval to enforce the Dayton Agreement, he has reinforced the dangerous and accumulating precedents around the presidential exercise of war powers.
Beginning with Korea, through Vietnam, and on to Grenada, Libya, Panama, and the Persian Gulf, presidents have taken the nation to war on their own authority. Sometimes, as with the Tonkin Gulf resolution, Congress has delegated its own powers. Other times, as with the 1991 Gulf war, it has belatedly acquiesced. What Congress has not done is meet its responsibility to act jointly with the president in determining how troops will be used.
The pattern in the current case has been typical. The president determines what United States security interests and ideals require. Congress grumbles, passes resolutions reminding the president that he cannot send troops without its approval, but fails in the end to cut off funds. Congress is driven to consider such drastic action because the president failed to insist on its approval.
Obviously, Mr. Clinton refused to admit he needed congressional approval because he feared he could not get it. This, in turn, encouraged Congress to behave irresponsibly. Both chose to serve immediate strategic objectives, rather than do the hard work of governance in accordance with constitutional norms.
Clinton is not alone in asserting the doctrine that he can act without Congress. A news story on the front page of The New York Times declared, ''President Clinton does not need the approval of Congress to send troops to the Balkans....'' Cokie Roberts, on National Public Radio, dismissed constitutional questions with a similar flourish.
What ground is there for this impatience? The Constitution says the president is commander-in-chief of the armed forces. Alexander Hamilton, answering criticism that this power might enable a president to take the nation to war, insisted that the president was merely the supreme military commander. The Constitution reserved for Congress the power to decide whether and where the nation should declare war.
Perhaps those who ascribe warmaking power to the president are referring to the War Powers Resolution. Passed in 1973 (over President Nixon's veto), the WPR directs the president to ''consult with Congress'' in every possible case, before sending armed forces into potentially hostile situations. He may then send the forces in, but only for 60 days. If Congress does not, by then, explicitly affirm the commitment, the president must withdraw the troops within an additional 30 days.
Presidents since 1973 have uniformly held that the WPR is unconstitutional, because it attempts to regulate a president's constitutional powers by a mere statute. But the Bosnia situation reveals another respect in which the WPR sets forth unconstitutional standards.
The resolution represents itself as an attempt to clarify the meaning of the Constitution. It says explicitly that it gives no new power that is not already included in the Constitution. By what authority, then, does it allow presidents to send troops into harm's way even for 60 days, without congressional affirmation?
Clinton cites the Bosnia operation as imperative to preserve NATO. But the NATO Treaty guarantees only NATO members protection against attack. If Copenhagen is attacked, the US promises to respond as if the attack had been directed at Boston.
Yugoslavia has never been a member of NATO. One can argue that some NATO nations (Greece? Turkey?) are threatened by Balkan chaos, but that is another matter. If the NATO Treaty really demanded action, why haven't we sent troops there during the past three years?
On the merits, Clinton has made a good case for sending American troops to enforce the Bosnian accord. But it is not a case that he, by himself, has constitutional authority to send them there.
It is particularly disappointing that Clinton has lost this opportunity to take a stand for sound constitutional practice in the exercise of war powers. In his speeches and those of his national security staff, he has stressed the importance of working carefully and candidly with congressional leaders. In the crises over Haiti and Bosnia, he has provided excellent examples of how such consultations should proceed. But in both cases, he yielded in the final hour to expediency, dispatching troops on his own authority.
The great danger of this course is suggested by reports that his deep ambivalence was resolved in favor of intervention only when he contemplated his own political prospects. Whether or not this speculation is true, it points to a serious flaw in the war-power doctrine.
The president, reportedly, is concerned about how it would look during next year's campaign if the ghastly slaughter in the Balkans dragged on. His opponents could play back his own harsh campaign rhetoric against President Bush and ask why he was still dithering four years later.
Presidents can hardly avoid taking political considerations into account at such a moment. That is one reason why it is wise to require that war powers be shared between president and Congress.
True, Congress has many weapons to rein in a reckless president. It can make its military appropriations conditional; or harass the president and force him to reconsider.
Meanwhile, troops are being dispatched, and extricating them becomes agonizing. That is why we must set procedures in place to involve Congress in the process of making commitments in the first place.
In the Persian Gulf, and now in Bosnia, we have been confronted with a fait accompli. Firm commitments had already been made, and troops were on their way, before the debate in Congress began. Elder statesmen like Brent Scowcroft are forced to say that the only thing worse than sending troops to the Balkans would be to undermine the president's commitment.
This is not the way our system was intended to operate. The framers involved Congress in the decision to use military force because they wanted to make sure there was a broad political commitment before embarking on such a venture.
It is not that Congress is wiser than the president. It is, as Lincoln said, because no one man should be able to take this nation to war.