In a visit to Qatar and Saudi Arabia this week, Hillary Clinton said that Iran "is moving toward a military dictatorship," and continued the administration's campaign for tougher sanctions against that country.

What could America's top diplomat hope to accomplish with this kind of inflammatory rhetoric? It seems unlikely that the goal was to support human rights in Iran. Because of the United States' history in Iran and in the region, it tends to give legitimacy to repression. The more that any opposition can be linked to the United States' actions, words, or support, the harder time they will have.

Second, it is tough for anyone – especially in the region – to believe that the US is really concerned about human rights abuses. In addition to supporting Israel's collective punishment of the Palestinians in Gaza, Washington has been remarkably quiet as the most important opposition leaders in Egypt were arrested as part of the government's preparations for October elections. Amnesty International stated that the arrestees were "prisoners of conscience, detained solely for their peaceful political activities".

So what is the purpose of a speech like this? The most obvious conclusion is that it is to promote conflict, and to convince Americans that Iran is an actual threat to their security. Americans generally have to be prepared and persuaded for years if they are to accept that they must go to war. The groundwork for the Iraq war was laid during the Clinton presidency. President Clinton imposed sanctions on the country that devastated the civilian population, carried out bombings, and publicly declared that Washington's intention was to overthrow the government. Although, as we now know, Iraq never posed any significant security threat to the US, President Clinton spent years trying to convince Americans that it did.

President Bush picked up where President Clinton left off; and President Clinton publicly supported his campaign for the war. So did Hillary, and she defended her decision in 2008 even as it looked like it might cost her the presidency.

President Obama is unlikely to start a war with Iran – which would likely begin as an air war, not a ground war – not least because he already has two wars to deal with. But, as in the case of the Iraq war, his secretary of state is preparing the ground for the next president that may have a stronger desire or better opportunity to do so. There is a strong faction of our foreign policy establishment that believes it has the right and obligation to bomb Iran in order to curtail its nuclear programme, and they have a long-term strategy. The public relations campaign is working. A new Gallup poll finds that 61% of Americans see Iran as "as a critical threat to US vital interests," with an additional 29% believing that it is "an important threat". It is not clear why anyone would believe this; even if Iran did obtain a nuclear weapon, which is still a way off, they would not have the capacity to deliver it as far as the US. Nor is it likely that they would want to commit national suicide, any more than a number of other countries that currently have nuclear weapons.

The Obama team's messaging is not nearly so successful with regard to the issues that the vast majority of the electorate will base their votes on in this year's elections: the most recent ABC News/Washington Post poll finds that 53% disapprove of his handling of the economy.

For the immediate future, foreign policy concerns will likely rank low, far behind the economy, for the electorate. But the Obama team's foreign policy will hurt Democrats in the future. If I believed what Hillary Clinton and the Democratic leadership are telling me, I would have to consider voting Republican. If it's really true that all these people just want to kill us for no reason; that it has nothing to do with our foreign policy or wars; that we can effectively reduce terrorism by bombing and occupying Muslim countries; and that terrorism is the country's most urgent security threat – then why not vote for the party that looks tougher? This will inevitably come back to haunt the Democratic party, as it did in the 2002 and 2004 elections.

Meanwhile, US military spending – by the Congressional Budget Office's relatively narrow definition of the department of defence budget – reached 5.6% of GDP in 2009. Just before September 11, 2001, the Congressional Budget Office projected this spending for 2009 at 2.4% of GDP.

The difference, over 10 years, is more than four times the ten-year cost of proposed healthcare reform.