Historian Paul Johnson‘s latest Forbes column suggests Republican presidential candidate Mitt Romney has a chance to repeat a key event in recent American history.

As long as America continues to have a weak and indecisive Administration, we can expect no resolute lead from Washington, either. Mitt Romney has yet to establish himself as a world figure, but he has an opportunity this summer and autumn to make the recovering U.S. economy—by far the world’s largest—pull its weight again.

The U.S. has the wonderful ability to speedily transform itself from a state of intense pessimism to one of vigorous optimism. I remember the dark days of the 1970s, when the enforced resignation of Richard Nixon and the stagnant years of Gerald Ford’s and Jimmy Carter’s presidencies combined to drive America’s admirers to near despair.

But then came the advent of Ronald Reagan. Within weeks of Reagan’s entering the White House America’s pulse was racing, there was a new sense of purpose and the Administration began acquiring the decisiveness and authority that became its hallmarks.

The recovery of America’s characteristic self-confidence was a political miracle. If Mitt Romney is elected the same thing could again happen. And it needs to happen for the world economy to get back on track to expansion.