Last week, I wrote about an issue that is just under the radar screen in the election campaign, but is bound to ignite soon.

I refer to the question of whether the United States should sign a status of forces agreement, or SOFA, with Iraq before President Bush leaves office. Such an agreement would define the future role of U.S. forces in that country. The United Nations mandate authorizing that presence expires at the end of 2008.

Democrats fear a SOFA would tie the hands of the next president on troop withdrawals, and they are gearing up to oppose it. I’d argue that it’s in the interest of Barack Obama that an agreement be signed this year.

First reports about this SOFA raised hackles in Washington and Baghdad. Rumors swirled about U.S. requests to authorize 58 bases, along with immunity for U.S. contractors such as the notorious Blackwater. (The United States has SOFAs with more than 80 countries, but none this fraught.)

A surge of Iraqi nationalism – plus negative pressure from Iran – spurred questions about whether the Iraqi parliament would deliver the required two-thirds vote to endorse an accord.

Recognizing they had overstepped, U.S. officials have backed off their early requests. My conversations with senior U.S. and Iraqi officials reveal a U.S. stance that has already shifted on the issues of most concern to Iraq, even as the negotiations continue.

Private contractors will not have immunity from Iraqi law; the U.S. military will no longer be able to detain Iraqis at will, but will coordinate with Iraqi officials on arrests of Iraqis and their transfer to Iraqi control; and U.S. military operations inside Iraq will be coordinated with Iraqi officials.

As for the “58 bases,” “these are the locations where the U.S. military now operates,” I was told by Iraqi foreign minister Hoshyar Zebari in an interview in Washington. “These are not permanent bases,” Zebari said. “Their presence depends on the authorization of the Iraqi government for the duration of the agreement.”

And what would that duration be?

“We are talking one or two years,” Zebari said. “Then (the SOFA) would be reviewed or terminated if the troops went home.”

What about claims that these bases might be used to launch a U.S. attack on Iran?

“It (the SOFA) would include a clear reference that Iraq would not be used for offensive action against our neighbors.” When I pressed as to whether the accord might permit U.S. troops to undertake “defensive” forays across the border with Iran, in retaliation for alleged Iranian attacks, Zebari quickly replied that Iraq “would not be used to attack other countries.”

He also stressed that the accord would be transparent: “This agreement would not be secret. It would be open and ratified.”

And, he added, “Nothing in the SOFA would oblige U.S. troops to defend Iraq.” (This is why SOFAs are considered executive agreements, not treaties, and do not require ratification by Congress.)

In Zebari’s telling, the SOFA is far less binding on a future White House than the blogosphere would have it. If either side can withdraw from a SOFA on one or two years’ notice, the agreement would not unduly tie the next president’s hands.

But what’s the rush to get an agreement now? Why not wait and give the next president the chance to shape his own terms? In principle, Iraq could ask the Security Council for an extension of the U.N. mandate – although this might be difficult to achieve at this late date.

The advantage of a SOFA lies in one key word: continuity.

The next president will take office at a time when Iraq is in total flux. Any assessments made now may be out of date by next February. Important progress in security has indeed been made, but that progress is fragile and could be reversed. The sectarian civil war has died down, but fighting for power is now going on within sects.

Iraq’s government is flush with oil money, but has not developed the capacity to deliver services and create jobs. Provincial elections are scheduled for the fall, but they may be postponed until early next year.

The next president, be he Democrat or Republican, will have to re-examine the Iraqi situation immediately upon taking office. He will inherit an Iraq at a crossroads: capable of inching toward a coherent state, but still fragmented and capable of further political and social collapse.

If that president is Sen. Obama, he will be under pressure from his base to begin withdrawing troops soon. But if Iraqi leaders show signs that they are starting to consolidate gains, he might well want to reconsider his withdrawal timetable. Ditto, if it appears that too quick a pullout would jeopardize those gains.

A Democratic president would not want to be blamed, whether fairly or unfairly, if things turned sour again in Iraq.

With a SOFA in place, a President Obama would find it easier to shape his Iraq policy. He would not be worrying about negotiations and would not be hindered from drawing down troops.

So my recommendation to Democrats would be to demand transparency from the White House on SOFA terms but not to try to fight the accord. Under Iranian pressure, the Iraqis may still do so, but that’s another story. A SOFA in time is the Democrats’ best bet.