President Barack Obama made his true international debut this week, with speeches and meetings at the United Nations, a summit with Israeli and Palestinian leaders, and the hosting of the G-20 conference in Pittsburgh. Obama's earlier international tours offered inspiring rhetoric and photo-ops, but they did not delve into the nitty-gritty realities of policy making and international diplomacy. This week was different. Eight months into his presidency, we are seeing Obama's approach to the world take shape. There is cause for both hope and for skepticism.

President Obama has just made an important breakthrough with Russia. Conservative critics vilified his recent decision to discard the Bush administration's missile defense strategy in central Europe as an abandonment of the Czech Republic and Poland. But the widely respected Secretary of Defense, Robert Gates, muted some of Obama's critics with his cogent explanation of the policy shift in missile defense. Hundreds of proven sea-based, medium-range missiles, Gates said, would make a better deterrent to a potential Iranian missile launch than would the 10 untested land-based, long-range missiles of the Bush plan. Additionally, rather than enhancing U.S. and NATO security, the Bush plan created a Cold War-style "security dilemma" with the potential for tit-for-tat escalation. Many foreign policy realists as well as liberals saw it as a gratuitous provocation that would antagonize Russia just as we needed its cooperation in dealing with Iran, North Korea and other hot-button international issues. Obama's decision to alter the missile defense strategy was welcomed immediately by Russia, which declared that it would no longer station its own missiles as a counter-move.

At the UN on Wednesday, we saw a potential payoff for Obama's missile defense decision. Russia indicated its willingness - for the first time ever - to support sanctions against Iran should that country refuse to halt its uranium enrichment program that could be used to develop nuclear weapons. Following his meeting with Obama at the UN, Russian President Medvedev declared that, "we need to help Iran to make a right decision," and that, "in some cases, sanctions are inevitable." This apparent shift in Russia's position would have been unimaginable had Obama kept the original missile defense plan intact.

The next day, Obama scored another foreign policy coup. Leading a rare summit-level session of the Security Council on Thursday, the American president convinced all 15 members-Russia and China included-to vote in favor of a US-drafted resolution calling for enhanced international cooperation in halting the spread and development of nuclear weapons. Although Iran was not mentioned by name, it was clear from the tough speeches made by the leaders of Britain and France that Iran was an intended target of Security Council Resolution 1887. The U.S. has laid the foundation for what could evolve into a robust, multilateral sanctions regime against Iran should negotiations fail to bear fruit.

At the G-20 summit in Pittsburgh Friday morning, Obama, with the leaders of Britain and France at his side, denounced Iran's second, secret enrichment facility and demanded international inspections. The test for Obama will come if and when the upcoming negotiations with Iran fail. There are times when talking no longer works and tougher responses are called for. Will Obama be able to convince the Permanent Five to take steps to enforce 1887, and lead the Security Council in isolating and punishing Iran if it flouts the will of the international community?

On the Israeli-Palestinian front, Obama has already devoted more time and resources trying to resolve the conflict in his eight months in office than did his predecessor in eight years. But it's been a tough sell. The Israeli public is highly skeptical of any peace deal with the Palestinians-especially given the increased rocket attacks that followed Israeli withdrawals from Lebanon and Gaza. Obama needs to convince the right-wing, pro-settler Netanyahu government to negotiate peace, but he also must convince the Israeli polity that doing so will not endanger the Jewish state. Lofty rhetoric won't suffice. The US will need to provide security guarantees to Israel, and shore up the pro-Western, anti-Hamas Palestinian Authority so it can keep its side of any bargain.

Obama understands that continued Jewish settlement expansion in the West Bank undermines the chances for a negotiated settlement. He also understands that the Palestinians are part of the broader Arab world and any successful resolution of the Israeli-Palestinian conflict will ultimately require a regional rapprochement. This is why he called for both a halt to Jewish settlement expansion and for Arab states to make tangible moves toward normalization with the Jewish state. But so far Obama and his foreign policy team have been met with intransigence on all sides. Left to themselves, the parties will never resolve this conflict. It is time for the U.S. to articulate its own comprehensive plan for Israeli-Palestinian peace, one that addresses the final status issues, and fully leverage our influence with the various parties to move it forward to completion. If President Obama is to succeed where his predecessors have failed, he will need to demonstrate strong leadership both in the region and with Congress.

A year from now the world, and the American public, will be judging President Obama not on his soaring rhetoric and lofty goals, but on his tangible achievements on specific policy issues and international crises. For some people his vision for America's global leadership is inspiring and refreshing. For others, it is hopelessly naïve. Either way, it remains to be seen whether Obama will have the strength of will and the leadership skills to deliver the goods, both at home and abroad. To paraphrase Teddy Roosevelt, President Obama succeeds quite well at speaking softly, but can he wield the big stick?