Amid uncertainty about whether the P5+1 and Iran would sign an agreement over the weekend, Israel urged patience Saturday night, advising the world powers not to rush and sign a "bad deal."The crippling economic sanctions, according to one diplomatic source, have put Iran into a position where it has no alternative but to make concessions in order to ensure the survivability of the regime."The minute the sanctions are removed the ability to compel the Iranian regime to make concession will be significantly reduced," the official said. The official reiterated Israel's position that there was no true significance in an Iranian agreement not to enrich uranium to 20% -- believed to be one of the Iranian "concessions" under the proposed accord -- even though they will retain the capabilities to do so."This is like a man on an elevator who says that he is giving up the right to go to the 20th floor, , but you leave in place the button for the 20th floor so he can push it whenever he wants, and even go to a higher floor," the official said.The official characterized the agreement as a "bad one" which should not be signed. "There is a need, and it is possible, to get a much better deal," the official said. "And if the Iranians refuse, then the world immediately needs to increase the sanctions."Senior diplomatic officials said that Iran has some 10,000 centrifuges in place, and another 8,000 – many of them faster, second-generation centrifuges – ready to install. By comparison, Pakistan – which already has a nuclear weapon – "only" has 6,000 centrifuges, one senior official said. Even if Iran gives up the enrichment of uranium to 20%, according to the source, it would take only 33 days for Teheran to be able to enrich its stockpile of 3.5% enriched uranium to the level needed for a nuclear bomb. In practice, therefore, the Iranian "concession" of giving up 20% uranium rolls back the nuclear weapon program a total of five weeks, he said.The official dismissed the argument that if an accord was not signed the Iranians would speedily move forward toward a bomb. If that does happen, he said, the sanctions could also move forward. "If there is no agreement, you can increase sanctions. The choice is not either an agreement or ware – there is another option, and that is tougher sanctions."If sanctions are ratcheted up, rather than scaled down, the Iranians will "sit down quietly" at the table because they will have no other choice, he said, adding, "when your foe is on the ropes, you keep hitting him until he surrenders."