News Analysis: Syria ceasefire marks big step forward, but remains fragile

The newly-announced cessation of hostilities in Syria marks a major step forward towards a political solution to the country's crisis, but analysts warn the ceasefire could be very fragile considering the complexity of Syria's situation.

On Tuesday, the Syrian government and rebel groups accepted a plan for a cessation of hostilities beginning Saturday, as agreed upon by the United States and Russia.

The ceasefire plan is welcomed by the United Nations as "a signal of hope" for an end to the nearly five-year-old conflict. However, analysts say its implementation faces many challenges as enmity between the warring sides remains.

The first source of concern here is the blurring distinction between extremists groups and opposition forces. In other words, who on earth are the "terrorists"?

In a joint statement, the United States and Russia made it clear that the ceasefire agreement will not apply to "Daesh," also known as the Islamic State, the Al-Nusra Front, or other terrorist organizations designated by the UN Security Council.

However, the boundaries between extremist groups and opposition forces are not so clear on the battleground of Syria.

As some analysts have observed, extremist groups are now increasingly infiltrating the opposition forces, and it is commonplace in Syria that several different armed forces form an alliance, uniting together to fight against government troops.

The rebel alliance Army of Conquest is a good example. The coalition,which has seized Syria's northwestern province of Idlib, is composed of dozens of small opposition groups which aim to overthrow the Syrian leader Bashar al-Assad, as well as a range of mostly jihadist and Islamist groups, the most prominent being Al-Qaeda affiliate Al-Nusra Front.

Secondly, government troops, backed by further Russian air strikes, might not be quite willing to stop military operations at a time when they have been gaining the upper hand in the prolonged conflict.

President al-Assad has said recently he was ready for a ceasefire in Syria only on condition that the "terrorists" did not exploit it.

He said in an interview with the Spanish El Pais Newspaper that for the truce to hold terror groups must be prevented from "using it to improve their positions."

He also insisted that any ceasefire deal must ensure that other countries are prevented from sending over more terrorists and weapons, or any kind of logistical support.

"If we don't provide all these requirements for the ceasefire, it will harm stability. It's going to make more chaos in Syria," the president said.

Washington's motives are a third source of concern. Andrew Tabler, an expert on Syria at the Washington Institute for Near East Policy, pointed out that "Washington's stated policy is not to end the Syrian war."

"They just want to settle it down so it boils a little more slowly. It's yet another attempt to contain a conflict that has been uncontainable," he said.

Tabler also added that true peace will not come until the regime of president al-Assad can reach an agreement with the opposition rebels. Endi