TRUE, THE WAR in the Persian Gulf does not threaten American motorists with gasoline lines. The well-remembered gasoline lines in 1974 and again in 1979 were the result of the price controls on oil. Since the price controls have been abolished, shortages are unlikely. Disruptions of suppply would instead result in higher prices -- perhaps startlingly higher. But for the present, the chance of that seems remote. Despite the intermittent bombing of tankers and the increasing prevalence of mines, the traffic to the Gulf's ports continues to be heavy, and the flow of oil -- so far -- has not been seriously affected.

But the industrial countries that run on oil, most prominently this one, would be prudent to think ahead. Americans should not take much comfort from the thought that there's a lot of excess capacity in the world -- that is, oil wells being pumped at less than full potential. Very few of those wells are in North America. Most are in the Arab countries. About one-fourth of the noncommunist world's oil comes from the Persian Gulf, and any significant interruption or hold-back in Gulf production is going to have a drastic effect on all of the industrial economies. The world has seen that demonstrated twice in the past 14 years.

Military interdiction -- a spreading of the war in the Gulf -- is certainly a possibility. Another and greater risk is political interdiction. The Arab countries on the southern rim of the Gulf have for some time been adjusting their oil policies to the rising influence of Iran and its demands for higher prices. Oil prices are not a bad barometer of the Arab estimate of Iranian power. The American, British and French naval forces now in the Gulf, by providing a substantial and visible counterweight to Iran, are doing as much as anyone this summer to preserve the economic stability of the democracies.

But the Persian Gulf is going to continue to be a dangerous neighborhood, and the big importers of oil need to reduce their dependence on it. American oil imports have been rising, not rapidly but steadily, since early last year. That only increases American vulnerability.

The administration talks vaguely about leaving oil consumption to the market. That's reckless. The market reduces consumption through great surges in prices, followed by severe recessions. The United States has been through two of those episodes since 1973, and they weren't pleasant. The alternative is vigorous conservation, led by public policy. It's not market economics, but it's a lot more attractive and, incidentally, more efficient than the other solution -- the third oil crisis toward which this country, in its thirst for oil, is once again slowly drifting