Despite some election-year posturing, the two major parties and their presidential candidates remain largely aligned when it comes to United States policies aimed at preventing Iran from obtaining nuclear weapons. This is important because when it comes to a situation this serious, the nation cannot afford missteps due to petty partisan confusion.

For all his affectation as Israel's best friend during his visit to that country and his questioning of President Obama's commitment to Israel's security, Republican presidential candidate Mitt Romney did not make any commitments that stray beyond current policy.

"Gov. Romney believes we should employ any and all measures to dissuade the Iranian regime from its nuclear course, and it is his fervent hope that diplomatic and economic measures will do so … In the final analysis, of course, no option should be excluded. Gov. Romney recognizes Israel's right to defend itself, and that it is right for America to stand with it," read a carefully worded statement issued by the Romney campaign.

That pretty much sums up the approach the Obama administration is taking.

While the regime in Iran persists in its nuclear course, the pressure on that country builds. Robert J. Einhorn, the State Department's special adviser on nonproliferation, told the New York Times that European and American sanctions on Iran have cut its oil exports by as much as half. Iran stands to lose $36 billion annually in oil revenues and its currency, the rial, has lost 38 percent of its value since the United Nations authorized sanctions last January.

The Obama administration, working with Congress, continues to turn up the pressure. In a rare show of bipartisanship, House and Senate leaders this week announced a series of new measures to keep Iran from circumventing existing sanctions. The United States will blacklist any financial institutions that receive payments for Iranian oil, and new measures would target products beyond oil, such as petrochemicals.

The goal is to drive Iran back to negotiations, this time with a credible commitment to reach an agreement, not just buy time. Necessary is an accord that includes verification provisions that assure the world that Iran is abandoning its pursuit of nuclear weaponry, while allowing that nation to develop the peaceful use of nuclear power.

In a meeting with Israeli Prime Minister Benjamin Netanyahu Wednesday, U.S. Defense Secretary Leon Panetta made the right point in stressing that all non-military means of pressuring Iran must be exhausted before considering military action. The repercussions of a military strike are impossible to know, but would include spiking energy prices that could pitch a fragile global economy into recession. Greater turmoil throughout the Middle East would seem assured.

Mr. Netanyahu's saber rattling response to Mr. Panetta was disconcerting. "Right now the Iranian regime believes that the international community does not have the will to stop its nuclear program. This must change, and it must change quickly because time to resolve this issue peacefully is running out, " he warned.

Yet the Israeli prime minister must recognize a raid by his country without U.S. cooperation will be far less effective and would generate substantial domestic opposition.

There may be no more important or difficult foreign policy challenge facing this and the next administration.