When Thai military negotiators met insurgent groups last August to lay the groundwork for formal peace talks, everyone at the table was a man.
If women had been involved, the chances of an enduring truce would have increased dramatically, according to a United Nations report.
An all-male turnout is common in many peace processes around the world, but the UN wants to rectify that to make agreements more sustainable.
Its two-year study on the role of women in preventing conflict and securing peace showed female participation increases the probability of an agreement lasting 15 years by 35 per cent.
Their involvement, says the report, shifts the dynamics of negotiations and broadens the issues discussed, thereby increasing the chances that the larger community would later rally around the deal reached.
Speaking at the Bangkok launch of the report, titled Preventing Conflict, Transforming Justice, Securing The Peace, Ms Hanny Cueva Beteta, a policy adviser at the UN's gender equality unit, told The Straits Times: "Here's the problem: We are trying to build peace, using only the perpetrators of violence... We need to put those who actually want to build peace at the same table with the ones who have the arms, and bringing women usually does that."
Not doing so risks sending the message that "you will only have a voice if you take up arms", she said on Thursday.
The study included a detailed analysis of 40 peace processes since the end of the Cold War, which found that having women on the front line of the process helped push for negotiations to start, resume or conclude whenever talks stall or momentum flags.
The comprehensive March 2014 deal between the Philippine government and the Moro Islamic Liberation Front, for example, was signed after 17 years of talks, which the women participants had demanded include public participation, including a national dialogue process.
The Philippine women civil society groups also protected negotiations from spoilers. In 2012, when three weeks of violence broke out between the militants and Philippine military, these women groups led peaceful protests to end the violence and maintain negotiations.
Commenting on the report, Thai National Human Rights Commissioner Angkhana Neelapaijit said having women as full participants in negotiations with southern Thai insurgents would make it easier to tackle gender-based violence such as sexual assaults.
Meanwhile, the report also calls for women's presence in UN peacekeeping and police forces to be ramped up. As of last July, women comprised only 3 per cent of the military in UN missions, with most of them serving as support staff rather than on the front lines.