WHEN the Iowa was last on active duty many of us still wore short pants. Built in 1942 and mothballed in 1958, it was recommissioned last Saturday, making it the second battleship on active duty in the United States Navy.
The recommissioning of the Iowa has military, diplomatic, and political implications. Like aircraft carriers, battleships symbolize the Reagan administration's policy of using the Navy - the most expensive of the armed forces - as a visible symbol of the projection of American might.
Whether the battleship serves a useful military purpose is a more arguable matter.
The Iowa has plenty of military power: old guns, including 16-inchers that can hurl a one-ton shell 25 miles, and new cruise missiles that can launch a nuclear warhead several hundred miles.
The New Jersey, the first battleship recommissioned, several times used its 16-inch guns to lob shells at Muslim positions during the US presence in Beirut.
Addition of the Iowa to active-duty ships advances the Navy further toward President Reagan's goal of a 600-ship Navy capable of controlling large areas of the world's oceans, and of attacking coastal areas from shipboard.
With these weapons the Iowa, like aircraft carriers and the New Jersey, is likely to spend much time steaming around oceans and to troubled areas of the world, furthering United States diplomatic strategy by showing the American flag and participating in maneuvers that emphasize its military potential.
The Iowa now is bound for the Caribbean, where American forces from Army, Navy, and Air Force are holding training exercises. These serve both military and diplomatic ends by warning Cuba and Nicaragua of American military power.
The Latin America exercises and the Iowa's participation in them also have the political purpose of reminding American voters in this election year that President Reagan repeatedly has expressed determination to oppose communist influence in El Salvador and other areas of Central America.
This theme plays particularly well in the conservative Southern states, likely to be important in the November presidential election.
Whether it was worthwhile to renovate the Iowa - and whether two additional battlewagons ought to be recommissioned - is debatable. The United States did obtain much more firepower for less cost, and more quickly, than by building new ships.
Yet the battleships are 40 years old, and ships so large are often considered particularly vulnerable. Then there is the argument that it may be destabilizing to world peace to put nuclear weapons on surface ships - in addition to having them on land and in submarines - and sail them close to a potential adversary's shores.
Discussion of whether a World War II battleship has a role in the Navy of 1984 eventually leads to examination of the Navy's doctrine of maritime superiority, a Reagan administration goal of long standing. Administration supporters hold that the Navy was sadly neglected for years.
But does the United States need a Navy able to project power in so many areas at once? Can it afford one? In order to find funds to build up the Navy to this degree, is the United States seriously neglecting both Air Force and Army strength - with the result that on balance America may be becoming weaker rather than stronger in more important areas?
The Navy is well on its way toward its goal of 600 ships and its strategy of maritime superiority. Yet the issues should continue to be raised in the future as Congress debates Defense Department requests and whether to finance the recommissioning of a third and a fourth battleship.