美国有线新闻 CNN 叙利亚停火协议开始生效 值得期待却不容乐观（在线收听）

We're starting today with a glimmer of hope in a civil war. The Middle Eastern nation of Syria has been torn apart since 2011. The United Nations estimates that 400,000 Syrians have been killed.

But earlier this week, a ceasefire organized by Russia and the U.S. officially begun. It calls for a stop to the fighting between Syrian government forces and the rebels fighting them. It does not apply to the terrorists fighting in Syria.

And while the ceasefire didn't stop all of the violence immediately, a relative calm had settled over the country on Tuesday. Officials hoped this will allow aid groups to get food and supplies to hundreds of thousands of Syrians who desperately need it. But some organizations were waiting on guarantees of security before setting out. Previous ceasefires in Syria did not last long.

SUBTITLE: The struggle for a ceasefire in Syria.

NIMA ELBAGIR, CNN SENIOR INTERNATIONAL CORRESPONDENT: What do you need for a successful ceasefire?

Well, sadly, there is no wave of the magic wand, but in essence, you need three factors to be present. You need trust, which is in extraordinarily scarce supply in Syria right now. You need a clear delineation of areas of control by the armed groups and armed actors. And you also need leverage to enforce the ceasefire.

In terms of the delineation, well, the situation on the ground in Syria is extraordinarily confused and you have a number of very strange bedfellows sharing frontlines. But that complicates things when you have international actors like the U.S. and Russia seeking to work together to target those actors on the ground that they have identified as hostile, mainly Jabhat Fatah al-Sham and ISIS.

But what happens when you have more mainstream oppositions in those very same territorial footprints? Well, then you need the mainstream opposition to agree to give up some of that territorial hold and withdraw. Now, that is not something any armed group anywhere in the world is particularly comfortable with, in order to enforce that. That's where the leverage comes in.

But given how many years the conflict in Syria has been, allowed to roll on with so little sense of any kind of peace coming over the horizon, leverage isn't something that really anyone in the international community has selfless add.