At a recent international conference, a colleague asked, "Now that Obama has been re-elected, will he finally earn his Nobel Prize?" It’s a fair question.

Hopes were high within the disarmament community after President Barack Obama pledged to move toward a nuclear-weapons-free world in his 2009 Prague speech. But those who cheered the loudest then are among the most disappointed now, because of slow progress.

Some key steps were taken. The 2010 Nuclear Posture Review reduced the roles of nuclear weapons in U.S. defense policy and Obama concluded the New Strategic Arms Reduction Treaty ("New START") with Russia, which reduces both nations’ nuclear-weapon inventories.

However, the administration’s willingness to seek ratification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) proved vain, as did efforts to conclude a fissile material cut-off treaty.

The Obama-initiated Nuclear Security Summit made advances, but the goal to secure all vulnerable nuclear materials in four years has not materialized.

Finally, the North Korean and Iranian nuclear crises remain unresolved.

While it would be unfair to blame Obama for failing to solve all these problems, it is important to reflect on what we can expect him to accomplish over the next four years. His administration faces three challenges:

» Improve strategic stability among major powers.

» Strengthen deterrence and reassure allies.

» Combat nuclear terrorism and proliferation.

In Asia, the major power agenda consists of two sets of relationships: One among the U.S., Russia, and China; the other among China, India and Pakistan. The U.S., Russia, and China deter one another. While Washington (and Moscow) may worry that deeper reductions may tempt Beijing to "sprint to parity," China’s "minimal deterrence" strategy already provides strategic stability.

China worries not only about the U.S. (and Russia?), but also about India, while Pakistan has been rapidly building up its arsenal in response to India’s military capabilities. Attempts by New Delhi to counter Pakistan’s moves would likely drive China to respond, which would affect the U.S. and Russia. Thus, major power relations will be determined mainly by decisions made in Beijing, New Delhi and Islamabad ― not in Washington.

Similarly, America’s ability to reassure its Asian allies is under stress. China’s slow but steady military modernization and North Korea’s nuclear development are raising concerns about the reliability of the U.S. extended deterrent.

Despite the U.S. "rebalancing" toward Asia, U.S. allies question the sustainability of the U.S. commitment in current fiscal circumstances. Some in Tokyo and Seoul argue for the development of independent nuclear-weapon capabilities.

Finally, the U.S. ability to combat the proliferation-terrorism nexus has proved limited. Although U.S. endorsement of nuclear disarmament has improved the atmospherics, little tangible progress has been achieved on the nonproliferation and nuclear security fronts.

Many Non-Aligned Movement members in Asia argue that the "baby steps" undertaken thus far toward disarmament do not justify more efforts from them on nonproliferation and nuclear security. Thus, U.S. power and influence is much more modest than often assumed to address nuclear challenges.

Nevertheless, the U.S. remains a critical player to generate change. This was illustrated during Obama’s visit to Myanmar when President Thein Sein announced that his country would agree to heightened nuclear monitoring. This decision is not only a measure of how much (and how quickly) Myanmar wants to change, but also how much it felt Obama’s visit needed to be acknowledged with a tangible deliverable.

Likewise, however apprehensive they may be about the U.S. commitment, U.S. allies continue to seek U.S. protection. And it would be foolish to think that major power relations will not depend on U.S. policy choices.

As his next (and last) four years begin, we need to have realistic expectations about what Obama can achieve. Hopefully, we will see U.S-Russian discussions on further nuclear reductions and the P-5 process initiated three years ago will produce tangible results and be expanded to include all nuclear-armed states to help stabilize the arms build-up in China and South Asia.

Entry into force of the CTBT would also be a major step, as would the opening of meaningful dialogues with Iran and North Korea.

Finally, U.S. allies need to embrace the non-nuclear dimension of extended deterrence and non-aligned states need to fully support efforts to combat proliferation and nuclear terrorism.

If Obama can help move the world in this direction, he will have earned his Nobel Prize.