Western nations insist on massively cutting Iran's capacity so as to prevent it from acquiring weapons-grade material, but Tehran refuses to comply, saying its enrichment is for civilian purposes only. On sanctions, Iran wants them to be lifted immediately while the West upholds a gradual removal to head off Iranian non-compliance.

If the big gaps cannot be bridged, the hard-won negotiations might have little chance to continue, and no one will benefit from it.

Once the talks broke up, the Iranian government might have to deal with even harsher pressure with more sanctions dampening its economy amid a global oil price slump. It is also possible that Iran's supreme leader, Ayatollah Ali Khamenei, may change its supportive positions for the talks.

As for the United States, had the talks gone broken, President Obama's diplomatic legacy will suffer a major blow and Washington may have to deal with a much more complicated security situation in the Middle East where turmoil and terrorism are raging. Moreover, the international community could suffer from a major setback in the integrity of global nuclear non-proliferation system.

In the future talks, the negotiators need to be courageous and open enough to deliver real compromises, and further promote their trust. Meanwhile, Iran needs to try even harder to convince the rest of the world of the peaceful nature of its nuclear program while the West needs to acknowledge Iran's right to peaceful use of nuclear power and scrap the sanctions if Tehran eventually complies.