This week's federal NDP convention will be a watershed moment in the party's history as it looks to turn the page on a turbulent few years.  Two years removed from the dramatic events at its preceding convention in Edmonton, the party has a charismatic new leader with a powerful mandate from members.Now, with little more than a year until the next federal election campaign kicks into gear, the NDP must offer a firmly progressive alternative: labour and the environment must be front and centre in all trade discussions; income inequality and the increasingly precarious nature of work must be addressed; the government's reversal on electoral reform needs to be confronted head on; rising xenophobia and racism in the wake of right-wing populism must be fought with a strong, inclusive vision that unites Canadians from all walks of life; and Canada's First Nations deserve to be top of mind as the Liberals fail – once again – to live up to their promises.As the NDP challenges the Trudeau Government on the central issues of our time, while simultaneously preparing for the challenges of the next federal election, the party also needs to unify.  It is only through a united movement that Canadians stand any chance of building an inclusive, sustainable, and prosperous future. This requires the participation of all progressive Canadians.Among the most contentious issues leading up to the convention is the Middle East and the Israeli-Palestinian conflict. Needless to say, this conflict is not the only international justice issue confronting progressives. The war on LGBTQ persons in countries around the world, the devastating crises in Myanmar and Syria, and the repression of workers and the labour movement fighting to protect them, command the attention, support and solidarity of progressive movements around the globe. What is unique about the Israeli-Palestinian conflict, however, is the extent to which it is emotive and divisive among progressives.But there are elements of the Israeli-Palestinian conflict that also demand our solidarity, such as those campaigning for peace and justice in Israel and Palestine.  In both places, moderates are being shunted to the sidelines as fundamentalists and nationalists dominate the discourse and put the two-state solution in greater jeopardy than ever.  Two sovereign states, for two peoples, where self-determination is guaranteed by secure borders and a lasting commitment to peace: this must remain the cornerstone of progressive policy in the Middle East.This weekend, NDP members should reject Israel's ongoing settlement expansion for the same reason members must reject boycott motions and resolutions to unilaterally recognize Palestine. These decisions should be agreed upon by Palestinians and Israelis – not imposed on them by foreign parties.  Only a negotiated resolution between the two sides can lead to lasting peace. Canada has a critical role to play, but prejudging solutions without this important step further imperils a two-state solution, and putting the exclusive blame for stalled negotiations on Israel further marginalizes Israelis at the forefront of the fight against the hardline Netanyahu agenda.Progressives must take a constructive approach. Taking a one-sided position is counterproductive and will only serve to exclude Canadian progressives from the search for a just and fair solution that supports an eventual two-state solution. While some may believe these policies offer the best contribution towards a peaceful resolution, they are ultimately unhelpful and should be voted down. They also run the risk of alienating many who are making important contributions to broader social justice movements and the push for modern, progressive policies. That is why one-sided resolutions on this issue should be clearly rejected by NDP members.What the NDP should do is reach out to Labour parliamentarians and activists in Palestine and Israel, in cooperation with the labour movement and other progressive voices, and build a credible dialogue that puts forward a progressive path to statehood for Palestine and peace for Israelis and Palestinians.  Social democracy is an international solidarity movement as much as it is an ideology, and building formal ties with progressives in the region, one that circumvents the destabilizing discourse of extremists, is the NDP's best chance to contribute to a better future in a troubled region.Noah Niznick is a former federal NDP staffer who served in a number of roles during the party's 2011-2015 tenure as the Official Opposition in Parliament. Based in Ottawa, he currently works as a public affairs consultant at Public Affairs Advisors Inc. and is also actively involved in grassroots efforts to engage young Jewish Canadians to foster political participation in the democratic process.