To avoid serious failures, it is essential to seriously consider the possibility that they will occur. This applies to the future of Israeli-American relations. Although the special relationship is strong, history teaches there is no guarantee it will remain this way. Hence, it is crucial to try and understand President Barack Obama, even if there is no way to predict his future behavior with total certainty.

One way of understanding leaders is by identifying the figures who have served as their models, and by trying to identify accordingly possible behavioral trends. Obama's model seems to be Abraham Lincoln. Let us, therefore, try to outline Lincoln's characteristics and modus operandi - as described in biographies - in five different areas. Despite the differences in personality and circumstances, this can help shed light on ways of thinking that may have a significant effect on Obama's policy vis-a-vis Israel.

As a leader, Lincoln developed a great deal and realized values, in spite of prior declarations and intentions. For years, for example, he had viewed slavery as essentially immoral; he also opposed its introduction in territories newly joining the union as states. Nonetheless, he didn't support a sweeping prohibition of the institution. Only in later stages of the Civil War did he change his policy and, in his capacity as commander-in-chief, abolish slavery. Similarly, we might surmise that President Obama may come to see ending Israeli domination of the Palestinians as a moral imperative, and to accomplish that he will be willing to reverse himself on previous intentions and deviate from earlier declarations.

Lincoln was that rare leader who combined a high level of morality with unusual skills as a politician and as someone who could get things done. He used these to create the Republican Party and to be elected president, something that a few years earlier hadn't seemed possible. Obama's meteoric rise suggests that he, too, possesses superb political skills. Therefore, if he decides to pressure Israel strongly on the basis of moral and realpolitik considerations - a la Lincoln - Israel is likely to find its friends in Congress and the Jewish lobby unable to stop him.

Lincoln was a realistic statesman, who considered the national interest through a long-term prism. One can't rule out the possibility that Obama will decide that the stability of Southwestern Asia requires changes in American Middle East policy even at the expense of his country's special ties with Israel - changes that, in his view, may well be in Israel's real national interest.

Lincoln hated bloodshed and was sensitive to the suffering of people (and animals). Yet, when it became necessary, he did not hesitate to lead the United States into a bloody civil war. And when he became convinced that he was being ill-served by some of his commanders, he turned to Ulysses S. Grant, endorsing his "scorched earth" policy, which broke the Confederacy's back. In the same way, one can expect Obama - despite his fervent desire to proceed by means of agreement and understanding - not to hesitate to use force if he reaches the conclusion that it is justified. Accordingly, one cannot rule out the possibility of the use of military force against Iran - or of sanctions against Israel.

Finally, Lincoln was distinguished by his great patience, but when it ran out he played the Southern states in such a way that it was they who were left looking responsible for initiating the war. The lesson in this for Israel is clear: Any attempt to gain time by treading water is likely to push Obama to take steps that will not be to Israel's liking.

Of course, it is not certain that any of these scenarios will actually come about, but neither would it be prudent to discount any of them. Israel has to consider the real possibility of a diplomatic crisis with the United States, and the chance that it may apply pressure that Israel is unable to withstand.

So much for the pessimistic prospects of American action. Indeed, if Israel acts wisely, there is reason for optimism. For one, there is no doubt that Obama is sincere in his commitment to the security of Israel. His tenure as president offers a rare opportunity to make progress toward peace - one that accommodates Israel's basic values, rights and security needs. But this depends on our taking the initiative and not being dragged along after others.

The clear conclusion to be drawn, therefore, is that Israel would do well to present the U.S. president, and soon, with a realistic plan for a comprehensive peace in the Middle East, based in part on the Arab Peace Initiative. Such a plan needs to be accompanied by a road atlas that leads - in stages, and with reciprocity - to establishment of a Palestinian state with limited sovereignty, Israeli withdrawal (roughly) to its pre-1967 borders, the granting of an appropriate status to a principal Islamic actor in the Holy Basin in Jerusalem, and a regional and international resolution of the Palestinian-refugee problem. Such a plan would also include reaching an agreement with Syria, which would have to cut its ties to the rejectionist front; the establishment of full relations with Israel by nearly all of the Arab and Muslim world; regional cooperation that would include preserving the stability of local regimes; reliable security guarantees together with maintenance and strengthening of Israel's military strength; neutralization of fanatical movements like Hamas and Hezbollah; and prevention of development of an Iranian bomb.

If we don't behave in this manner - if we hold firm to past concepts and don't craft a new political-military paradigm - the opportunity inherent in the Obama presidency is liable to turn into a serious risk.

Israel Prize winner Yehezkel Dror served as founding president of the Jewish People Policy Planning Institute, and is emeritus professor of political science at the Hebrew University of Jerusalem.