Whoever wins the American presidency in November will come up hard against what former president Dwight Eisenhower described as the "military-industrial complex".

After the military build up of the Bush Administration, which now makes the US armed forces greater in size than all the other militaries of the world added together, the vested interests in the military-industrial complex have never been so formidable.

After years of stupendous growth of everything from tanks, to rockets, to aircraft and ships the providers of such do not want to see the upward rise of their business stymied by a new president. They have their ways and their means of influencing any president.

A president that tries to cut them down will find himself under a sophisticated public assault from members of Congress with large defence industries in their constituencies, a sizeable section of the press that historically has been easily seduced by the argument for an all powerful America, and too many academicians, who should know better, who have been showered with research contracts from military businesses. Not least there is the military itself, apt at out-manoeuvring secretaries of defence who want to change old ways of doing things- look at the legacy of such secretaries as liberal Les Aspin and conservative Donald Rumfeldt.

Public opinion, judging from recent history — the reasons given for going into Vietnam and Iraq — is easily brainwashed. Whatever the issue, one of the arguments always given for military intervention is the need to turn the tables on the anti-democrats and make the world a safer place for present day democracies.

America is most unlikely to bring democracy, as the Greeks knew it, to Iraq and Afghanistan. All the American wars in Southeast Asia turned out badly. Even in Somalia with the only enemy unsupported local militants America could not bring democracy. Only in the rarest of cases — Liberia comes to mind — an offshore presence in peacekeeping mode can help back up what negotiations have already arranged.

Where democracy was successfully created — in Germany, Japan and Italy — the US and its allies had to conquer and occupy foreign territory, grant generous economic assistance and defend the new governments from external threats.

American democracy itself has taken 200 years to mature and is not there yet. The enfranchising of its black population is a relatively recent development. The 10th Mountain Division could not have speeded that evolution up. Nor can it press the pace of other countries' evolution.

Proponents of a strong American military recite the lessons of the 20th century's two World Wars — that big wars elsewhere eventually suck in powerful nations, and the US should be well prepared. But this is a very selective view of history.

Neither the British nor the French were dragged into the Russo-Japanese war. Indeed, the American president, Theodore Roosevelt, ended it by arbitration, his famous big stick left behind in a White House closet.

The British stayed out of the Franco-Russian war when Napoleon got defeated after reaching Moscow, a great and bloody war beautifully documented in Tolstoy's "War and Peace", and both the British and the French stayed out of the Austro-Prussian war.

Some historians go further and say it was not necessary for the U.S. to declare war against Nazi Germany. The Russians, who did most of the job of defeating the Germans, would have done it eventually on their own. The subsequent Cold War and the nuclear missile race would then have been avoided. Nuclear proliferation would never have occurred.

"The US is not doomed by the laws of nature to go overseas and fight", writes a MIT professor of political science, Harvey Sapolsky. "In fact the US probably has more choice about the wars it fights than any other nation, because it does not share borders with other great powers."

What anyway does the US have to fear? The proliferation of nuclear weapons, yes. But as the cases of North Korea and Iran today are now proving, war is not an option when the weapons and laboratories are so carefully concealed. Moreover, those that have renounced their nuclear bomb programmes — Libya, South Africa, Brazil and Argentina — did it voluntarily or by negotiation.

Asian might? But no one can unite the industrial resources of Asia. Even China, as far as the eye can see, will be pouring all its energies into developing its vast territory and will have no interest in picking a fight with outside great economic powers.

A new president must re-educate the American public to a new strategic reality. It will require a very determined and brave president even to initiate the task.

But it has to be done, both to make the world more stable and to provide the funds to meet the desperate outcry of social need within the US itself.

Jonathan Power is a veteran foreign affairs commentator based in London