Editor's note: Professor Shen Dingli is director of the Center for American Studies at Fudan University. In this interview with the People’s Daily, he answers questions about US-Russia talks on the START follow-on treaty.

PD: The Strategic Arms Reduction Treaty (START-1) was signed in 1991 and expired on Dec. 5, 2009, but its successor has not yet been signed. Why not?

Shen: For both political and technical reasons. Politically, Russia needs to balance strategic arms reduction with its strategic defense. It is unhappy with American plans for a new missile defense system in Eastern Europe as an alternative to the Bush-era missile defense shield program. Moreover, it wants the treaty give equal rights and responsibility to both countries – particularly in regard to proposals to reduce mutual inspection and verification on missile production and disposal, and for the two countries’ congresses to approve the treaty in step. Technically, Russia needs more time for the production of a bilingual version of the new treaty detailing counting methods, missile reduction priorities, delivery systems, and restrictions on research and development of new types of intercontinental missiles.

PD: The Russian Foreign Minister recently said that the two sides may sign the new treaty as early as February. Why have negotiations restarted?

Shen: The two sides have agreed 95 percent of the content of the new treaty. The outstanding points are waiting on final concessions by the top leaders. History since the end of the Cold War has shown that neither Russia nor the U.S. needs strategic nuclear arsenals on their current scale. Bearing in mind its decline in overall strategic strength, Russia wants to pull the U.S. into bilateral negotiations on nuclear disarmament to protect its national security and preserve its strategic status. The U.S. does not need its current arsenal to preserve its overall advantage. Nuclear disarmament negotiations with Russia may enable the Obama administration to contain Russia, prevent nuclear proliferation, and make progress on the goal of zero nuclear weapons. The new treaty meets the needs of both sides and for that reason is certain to be signed.

PD: What can we expect from the new treaty? What difference will it make to regional and global security?

Shen: Russia and the U.S. agreed last July to cut warheads to between 1,500 and 1,675, and delivery vehicles to between 500 and 1,000 within seven years of the treaty taking effect. Both sides are working toward this agreement and the U.S. hopes to complete it before this April. Considering the current international security situation and the two sides' respective security strategies, the only question is when the new treaty will be agreed. Once agreed it will improve and stabilize the US-Russia relations, reduce the nuclear threat in global politics, create a favorable environment for the United Nations to review the nuclear non-proliferation treaty, and help consolidate regional and global strategic stability.

PD: What will be the effect if the U.S. and Russia fail to sign the new treaty?

Shen: It's almost certainly not going to happen. Failing to sign the new treaty is in neither side's interests. The U.S. and Russia have more than enough nuclear weapons. The weapons are heavy burdens on their economies and are limiting the development of their approach to security. Massive nuclear arsenals carry huge management problems and impede the progress of nonproliferation. Nuclear proliferation in Northeast Asia, South Asia and the Middle East are major threats to the whole process. Both sides are eager to agree the treaty as soon as possible, but persuading domestic oppositions may take longer than expected. For example, there will be mid-term elections to the US Congress this year, which adds uncertainty to the issue. What counts in the end is not the approval of Obama administration but whether the treaty survives votes in the Senate and the House.