Two or three times a week Defense Minister Ehud Barak's bureau receives a telephone call from the White House. On the line is Biden - Vice President of the United States Joe Biden. The conversation between Joe and Ehud is almost always friendly, almost always solving difficult problems amicably.

Joe is what America used to be and Ehud is what Israel used to be. Together they're trying to restore the American-Israeli alliance to what it used to be.

The frequent telephone calls between them constitute the alliance's lifeline. When the president in Washington and the prime minister in Jerusalem can't tolerate each other, the vice president and the defense minister function as the responsible adults. This is the strategy between two states, whose close relations have become frosty.

Barak's close relationship with Biden is one of the main reasons Prime Minister Benjamin Netanyahu treats his defense minister with great respect, almost reverence. Here are the other reasons. Netanyahu knows that without Barak his government will become a repulsive right wing government that wouldn't survive for long. Without Barak, Netanyahu knows Israel will become a pariah state, ostracized from the community of nations. The prime minister also knows that without Barak nobody will stand beside him when he makes a decision about Iran. Politics, policy and strategy all make Barak the central pillar of Netanyahu's government. Without Barak, Netanyahu has no future.

The opposite is also true. Without Netanyahu, Barak has no future. Barak knows that without the unique status afforded him by the partnership with Netanyahu, his party would eat him alive. Without Netanyahu, Barak knows his political status is in critical condition. He also knows that without Netanyahu no peace process can make progress in the near future. He understands that without Netanyahu it is hard to make a responsible, rational decision regarding Iran. Politics, policy and strategy all make Netanyahu vital for Barak. Consequently the defense minister feels something about the prime minister he rarely experiences - respectful veneration.

For years people have been talking about Netanyahu and Barak as if they were twins. But the truth is that only mutual dependence between the two has turned them in the past year into a pair of twins, the likes of which were never seen among Israeli leaders. David Ben Gurion and Moshe Sharett had a complex relationship, as did Levi Eshkol and Moshe Dayan as well as Golda Meir and Dayan. Relations between Yitzhak Rabin and Shimon Peres were poor, and those between Menachem Begin and Ariel Sharon were terrible. Yitzhak Shamir, Netanyahu during his first administration, Barak, Sharon and Ehud Olmert didn't really have partners. So the goings on between the prime minister and defense minister now are unprecedented.

The twins spend three, four or five hours a day in each other's company. There are no intrigues, tricks or leaks between them, no bad blood or petty politics. Even when they fail together, like in the Gaza flotilla incident, they stand together. This alliance is the axis upon which today Israel's politics, policy and strategy revolve.

But the Siamese twins are not identical. Although conjoined, each has different genetics. Netanyahu's inner circle believes that any concession is suicide. Barak's inner circle believes that the status quo is suicidal. Thus, when the twins sit alone in the room, two opposing world views accompany them.

For the twin alliance to survive, one of the two will have to change. One of them will have to turn against the ideological and identity-based DNA that forged him.

The flotilla and NPT crises have made this situation perfectly clear. Israel is losing its freedom of action. The country is on the brink. So the twins don't have much time. Only if they succeed in bringing themselves to take substantive action, can they save themselves and their country. If they don't do that soon, even Biden will stop calling. The two, who are hanging together, will find themselves hanging separately, politically, in the square of disgrace.