How peace in syria can be resolved?

Syrian civil war started in March 2011, as a result of protest against the rule of president Bashar al-Assad. Now this conflict has entered its 6th year and many think tanks and analysts are presenting their opinions on how to solve this conflict and prevent more bloodshed.
How it all started:
It all started in 2011 in the Syrian city of Deraa. The protest started when the police arrested 15 school boys and tortured them for drawing anti government graffiti on the walls. The protests were peaceful in the beginning; they demand the release of the children, democracy and greater freedom for people in the country. The government responded angrily and, on 18 March 2011, the army opened fire on protesters, killing four people. The next day, they shot at mourners at the victims' funerals, killing another person. People were shocked and angry at what had happened and soon the unrest spread to other parts of the country.
Civil war:
The protesters only demanded democracy and freedom but things took a wrong turn when the government forces open fire at the peaceful protesters. After this event their demands were converted in to one single agenda to end the rule of Bashar al-Assad. But he refused to step down which increased the anger in the people of Syria. various groups of rebels came out who just wanted Bashar to step down and the acts of violence increased to a level where in 2012 the international red cross declared it a civil war.
Intrusion of IS:
This wasn’t left just a civil war when an extremist group called Islamic state (IS) entered the eastern Syria from Iraq. They successfully gained their land and power in Syria chaos and havoc in the country. Now both groups (gov and anti-gov) had to fight against each other and the IS. Evidence abounds that, at the beginning of this crisis, Assad facilitated and manipulated ISIL as one of the tools in his political survival toolbox. (Randa Selim, Al Jazeera 2015/09)
2014 air-strikes and military action:
To stop IS in September 2014 countries like UK, US and some other countries decided to attack IS fighters on the grounds of Iraq. On 2nd December 2014 members of parliament of Syria voted in favor of military action in the country.
Since then people of Syria are in desperate need of help.
What should be done now?
Countries like US and Russia who have played a great deal in the Syrian game should come forth and take necessary steps to find a political solution for this conflict.
Randa Selim, Director of the Initiative for Track II Dialogues at the DC-based Middle East Institute and non-resident fellow at the Johns Hopkins University SAIS Foreign Policy Institute told Al-jazeera:
Russia is reluctant in protecting Assad’s government, In 2013, Russia engineered the chemical weapons deal that prevented Assad's downfall, at a time when the regime was weak, and US air strikes could have brought about the end of the Assad regime.
Vladimir Putin has invested in Assad's survival, and it is naive to assume that he will be willing to abandon him unless the cost of propping him up dramatically increases.
Koert Debeuf Visiting research fellow at the Centre for the Resolution of Intractable Conflict at the University of Oxford told Carnegie Europe:
There is no political solution for Syria because Russia and Iran don’t want one. Their strategies are very different from the West’s. Iran clearly wants to create a sphere of influence from Tehran via Baghdad and Damascus to Beirut. In Syria, a mainly Sunni Muslim country, any political solution will lead to the end of the power structure of President Bashar al-Assad and thus the end of the influence of predominantly Shia Iran.
For Russia, the war in Syria is about much more than Assad. The goal of Russian President Vladimir Putin is to destabilize and weaken the West. He wants to end the EU’s and NATO’s attractiveness to countries he considers part of the Russian sphere of influence. Russia is not targeting the self-proclaimed Islamic State but Syrian opposition forces. He is pretty happy with the massive refugee influx in Europe as this is destabilizing the union.
Phyllis Bennis wrote in” the nation”
The Obama administration should support United Nations decision-making, international law and diplomacy instead of military force, and make good on its frequent acknowledgment that “there is no military solution in Syria.” That means no US military strikes or threats of strikes, and an end to all other military involvement, including arms shipments. This is a point of principle, not timing—because even if efforts for a cease-fire, arms embargo and diplomacy do not succeed immediately, we know that US military involvement will only make things worse.
Washington should call for, and support, an immediate cease-fire by all sides and a comprehensive international arms embargo. It should announce immediate plans to stop sending or enabling the provision of arms to rebel forces and to prevent US allies from doing so, while simultaneously renewing pressure on Russia and Iran to stop sending arms to the Syrian government. Such a call on Russia and Iran would carry far more credibility if it was linked to a public US commitment to end its own arms provision.
Despite the resignation of special UN envoy Lakhdar Brahimi, the Obama administration should engage with Russia to urge the UN to take the lead in restarting international negotiations for a political solution.
All the developed countries which have previously got involved in Syria conflict must unite on a single platform and try to find the political solution and do what they have to do in order to stop the conflict and shedding of innocent blood.