In this tail end of summer, when millions of Americans are on vacation and the pace of national life slows, ominous sounds fill the airwaves. The talk is of weapons and war, strength and survival. The Republican presidential candidate evokes Vietnam as a "noble cause" and warns darkly of the precedent of Korea, "our first 'no win war,' a portent of much that has happened since." The Democratic administration, countering charges of national military weakness, responds with rhetoric of its own and lets it be known we have developed a wondrous new weapon, an "invisible plane" code-named "stealth" whose configuration defies enemy radar. The radio reports the rumor that five American hostages have been executed in Iran, stirring further forebodings.

It is as if somehow, in this lazy season of drift at the beginning of a new decade, we are stumbling into an abyss with no one capable of checking the fall. The analogy with the summer of 1939 just before war began, when an American living in Paris wrote in his diary that "everyone's daily life seems to be saturated with these feelings of apprehension," is, one hopes, false. But as an indication of the kind of discourse we will be hearing in the next two months of the presidential campaign, last week's words hardly inspired new confidence in national leadership, particularly in the quality of the challenger.

Ronald Reagan's performance in the opening days of his formal campaign as the GOP's nominee offers evidence he is not up to the job he seeks. His best hope of winning the White House lies in convincing the American people that, unlike his opponent, he is competent and capable of articulating a vision of the future and a clear sense of national purpose. His actions on the stump leave just the opposite impressions. He needlessly has aroused new doubts about his abilities and judgment.

In dispatching his running mate, George Bush, to China, he made them both look foolish by talking about establishing official relations with Taiwan. The Chinese were understandably furious, and Reagan and Bush were put on the defensive by having to try to explain just what Reagan really meant. In speaking to the Veterans of Foreign Wars convention in Chicago, Reagan again created unnecessary problems for himself. It wasn't just his references to Vietnam; it was the defiant way he courted controversy over one of the most painful episodes in the American experience.

Reagan couldn't let it lie there undisturbed. He deliberately stirred the fires with the old trigger words: The Vietnamese had a plan "to win in the field of propaganda here in America what they could not win on the field of battle in Vietnam." The American leaders betrayed our young men by letting them fight and die in a war our government was "afraid to let them win."

Later, in the same speech, he reached back a generation to resurrect a conspiracy theory long cherished by the far right -- that of Washington policymakers following a course of appeasing the Soviets. His point was about American military weakness and what he called Jimmy Carter's lack of coherent policy, his vacillation and indecision. Then he said:

"Or is there another, more frightening possibility -- the possibility this administration is being very consistent, that it is still guided by the same old doctrine that we have nothing to fear from the Soviets -- if we just don't provoke them."

Reagan accomplished by such words just what he needed to avoid. He reinforced the idea that he was narrow, combative and reckless instead of measured, careful and statesmanlike. That surely was not his purpose, as a careful reading of his texts strongly suggests.

In both addresses to the VFW and to the American Legion in Boston, Reagan seemed intent on showing he was not an ideologue but a more moderate figure who spoke from the mainstream of American life. He was not against detente per se; as he said, "relaxing tensions is a delicate and dangerous but necessary business." He was not against arms control negotiations; he said, "I think continued negotiation with the Soviet Union is essential." Nor was he seeking an increase in American arms merely for the sake of brandishing more weapons; he struck, on the contrary, a tempered note.

"For a nation such as ours," he said, "arms are important only to prevent others from conquering us or our allies. We are not a beligerent people. Our purpose is not to prepare for war or wish harm to others. When we had great strength in the years following World War II, we used that strength not for territorial gain but to defend others. Our foreign policy should be to show by example the greatness of our system and the strength of American ideals . . . "

Quite reasonable and highly responsible, all in keeping with his citing, approvingly, of the defense policies of Harry Truman and John Kennedy. The trouble is that's not what attracted attention, at home and abroad. For that, Reagan has only himself to blame. He mixed his own message and threw his own brand of gasoline on the olive branch he dropped.

These initial Reagan campaign documents are revealing for other reasons. Reagan, the foe of bureaucracy and big government, the prudent exponent of conservative approachers to Washington, has been sounding a most different signal on the campaign trail. He wants to increase veterans' benefits, substantially raise military pay and allowances and rebuild the U.S. maritime industry, all the while boosting defense spending and not cutting existing government programs. Although he doesn't spell it out, the money to pay for all this would come from the federal treasury and the benefits and the rest would be administered by those despised federal servants.

One last observation. Reagan's detractors have portrayed him as the candidate of nostalgia, a political performer whose be-bop instrument dates from an antediluvian choir. His own words lend credence to that charge.

He seeks, he says, to lead "a great cursade to restore the America of our dreams." In his first address, he cites the examples of Will Rogers and Jack Dempsey. How relevant -- or even how much remembered -- Rogers and Dempsey are in the apprehensive America of the 1980s others will judge, but both of them had passed their respective peaks of glory when Reagan was still in college some 50 years ago.