Sept. 18 (Bloomberg) -- President George W. Bush comes to the United Nations tomorrow with limited diplomatic leverage to block the nuclear ambitions of Iran and North Korea, largely because of fallout from the Iraq war, according to envoys.

Bush's decision to invade Iraq in 2003 without UN backing has intensified resistance to using the threat of force as a tool of diplomacy in the nuclear disputes. France, Russia and China --all of which agreed to put the threat into the UN Charter in 1945 -- are reluctant to authorize the step.

``The lesson we learned is that we have to be very careful,'' Chinese Ambassador Wang Guangya said. ``It has to be a clearly defined threat to international peace and security. Iraq is the example that put all of us in a difficult position.''

The U.S. suspects that Iran and North Korea, both part of what Bush in 2002 called an ``axis of evil,'' are developing nuclear weapons and could supply them to terrorist groups.

Bush, in a speech to the General Assembly tomorrow, will touch broadly on the nuclear disputes involving Iran and North Korea, according to administration officials. Bush also plans to raise the issues in private talks, the officials said.

In the speech, the president also will seek tougher measures to halt massacres in Sudan and abuses in military-run Myanmar, according to Assistant Secretary of State Kristen Silverberg. ``This is a time of real opportunity for the Security Council, also a time when we are really testing its resolve,'' Silverberg said in an interview.

Resolutions Weakened

The Security Council adopted four U.S.-backed resolutions during the past two months, on Iran, North Korea, Lebanon and Sudan, and in each case the U.S. and its allies were forced to drop or dilute references to the UN Charter provision that authorizes military action.

While Bush hasn't ruled out military action to disarm Iran and North Korea, the U.S., with 147,000 troops dealing with increasing unrest in neighboring Iraq, is constrained from a unilateral use of force.

Still, U.S. Ambassador to the UN John Bolton has said that if Security Council demands aren't backed up by a threat of force, Iran and North Korea would be emboldened to advance their nuclear programs and block unfettered inspections.

Bush will be the second of more than 80 world leaders to speak at the opening of the 61st session of the General Assembly. Secretary of State Condoleezza Rice is accompanying him to New York, and will stay throughout the week to hold meetings on topics including Iran and North Atlantic Treaty Organization policy.

`Perfect Storm'

They will find a UN membership still influenced by Bush's decision to sidestep the UN on Iraq, according to Jeff Laurenti, international affairs analyst for the Century Foundation, a policy research group in New York.

``You have a perfect storm of global rejection of U.S. leadership that has been taken for granted for 60 years,'' Laurenti said. ``This is a very strained time for U.S.-UN relations, and it all centers around Washington's apparent contempt for the obligations of international law in Iraq.''

Bush told reporters on Sept. 15 that he believes the Security Council has reached a consensus on Iran and that the government in Tehran must obey its demands. ``Part of my objective in New York is to remind people that stalling shouldn't be allowed,'' he said.

With few exceptions, UN resolutions imposing sanctions or establishing peacekeeping operations have cited Chapter 7 of the Charter, which includes the threat of ``action by air, sea or land forces as may be necessary to restore international peace and security.''

Russian View

Russian Deputy Ambassador Konstantin Dolgov, whose government supported sanctions against Iraq backed by the threat of force, said there is reluctance to include such language now. ``We have to learn our lessons,'' he said.

``People did not look at Chapter 7 with suspicion before Iraq,'' Wang said.

To win the support of China and Russia, the U.S. dropped a reference to Chapter 7 in the resolution adopted on July 15 that bars North Korea from acquiring or selling nuclear technology and demands that it suspend its nuclear program.

Instead, the text contained a limited reference to the Security Council's ``special responsibility for the maintenance of international peace and security.'' An Iran resolution on July 31 states only that the council ``shall duly take account of failure to comply.''

Chirac on Iran

French President Jacques Chirac, who also will address the General Assembly tomorrow, stressed his reluctance to back sanctions on Iran, telling Europe 1 radio that the dispute can be resolved through talks with the government in Tehran. Once talks begin, the UN should lift the threat of sanctions and Iran should agree to suspend its uranium enrichment during the discussions, Chirac said.

Chirac said in a later interview on CNN that ``multilateralism'' as expressed through the UN is ``the world's conscience'' and the sole solution to global problems.

The persistence of violence in Sudan's Darfur region also has caused friction at the UN. Sudanese government officials oppose the proposed peacekeeping mission to Darfur because they fear it could ``result in another Afghanistan or Iraq,'' Jean- Marie Guehenno, the UN's head of peacekeeping operations, told the Security Council in June.

Sudan's Resistance

China and Russia supported President Umar Hassan al- Bashir's resistance by abstaining from the Aug. 31 vote on the resolution authorizing deployment of the mission with Sudan's consent. Bush said last week that the UN should override Sudan's objections and send in a force ``in order to save lives.''

Bush cited the protracted action on Darfur, where he says genocide is being carried out, as one of his frustrations about the UN.

Ambassador Augustine Mahiga of Tanzania said that even Security Council members such as the African nation are reluctant to invoke the mildest sanctions, including travel bans and freezing overseas assets for Iranian officials, out of concern for the next steps the U.S. might seek.

`Bleeding Wound'

``Iraq is a bleeding wound in world politics, and everyone is paying a price,'' Swedish Foreign Minister Jan Eliasson, the outgoing president of the General Assembly, said in a news conference last week.

Silverberg said the U.S. got what it needed in resolutions such as the one on North Korea.

``There is no requirement that the Security Council use some magic words,'' she said. ``We think the Security Council is capable of speaking with resolve, and that is what we expect it do to in the case of Iran.''

Bush can make some progress in building consensus for U.S. priorities in his speech to the General Assembly, said Tim Wirth, a former Democratic senator from Colorado who heads the Washington-based foundation set up by billionaire Ted Turner to support the UN.

Wirth expects Bush to praise Secretary-General Kofi Annan for helping to negotiate an end to Israel's blockade on Lebanon and for mediating talks on the release of two Israeli soldiers held captive by Hezbollah.

``He will be the charming George Bush he can be,'' Wirth said. ``But it will take a lot of trust building and a lot of diplomacy to heal the wounds and allay a lot of suspicions. The president has a tough row to hoe.''

To contact the reporter on this story: Bill Varner in United Nations at wvarner@bloomberg.net.

Last Updated: September 18, 2006 10:58 EDT