For many of us in Europe, the relationship with Israel and Palestine is quite personal. For me, for instance, it is a longstanding one. After I finished university in 1969, I worked in a kibbutz when the State of Israel was still building itself. I traveled all over Israel and the Palestinian territories, from Galilee to Eilat and met my first wife in Gal On. This was my first contact with the still lasting Israel-Palestinian conflict. As a European, it reminded me of the often tragic nature of human history and to look for peaceful solutions to conflicts. My family and I came back many times, and in 2005, I spoke before the Knesset as president of the European Parliament, recalling the EU’s commitment to Israel’s security following the Second Intifada. At that time, there was still a widely shared sense of hope that, despite the setbacks, a two-state solution was still within reach. The EU and its member states have been consistently very active in supporting the two parties toward this goal. We helped build the Palestinian institutions in preparation for statehood, with financial support now reaching more than 600 million euros a year.We also understand Israeli concerns and are committed to Israel’s security, which is non-negotiable for us. The EU invests in cooperation that benefits both sides, on issues from counter terrorism to research, from tourism to the environment. We should be looking at ways to nurture this and develop our relations still further.Once the political process stopped, conflict and entrenching occupation became daily life. In the last years, there has been little progress. But the current status quo does not provide satisfying answers and is no sustainable situation. The hard truth is that only a return to real negotiations can give Israelis and Palestinians what they rightly crave: sustainable peace and security.For us in Europe, it is painful to see the prospect of the two-state solution, the only realistic and sustainable way to end this conflict, at risk. The project of annexation as announced by the government would mean the end of this solution. EU Member States think that the annexation would violate international law and we are using every opportunity with the Israeli government to explain this, in a spirit of friendship.Annexation affects people. It affects not only Palestinians, but also Israelis, the neighborhood and even us in Europe. Any violation of international law, particularly when involving the annexation of territories, has implications for the rules-based international order; it can therefore also affect negatively other conflict zones.Annexation is not the way to create peace with the Palestinians and to improve Israel’s security. It will not strengthen the negotiations process as some have suggested. Negotiations should begin from the international parameters, and build from there. Ultimately, neither Palestinians nor Israelis are going anywhere, so you must find a way to make peace between you. And there are examples of cooperation between the two sides; these should be commended and expanded not undermined.Damaging the international system by eroding one of the fundamental post-war norms that has made the world a safer place and legitimizing the acquisition of territory by force will always be unacceptable for European Union. Unilateral annexation will have negative consequences for the security and stability of the region. It would endanger Israeli peace agreements with its neighbors; it would seriously damage the Palestinian Authority, and any prospect of a two-state solution. Can Israel take responsibility for millions of Palestinians living in the West Bank with all political and social consequences? In sum, it would not solve any problems, but create more, including for security. In the international debate on the issue, this view has also been expressed by a growing number of important Jewish personalities and organizations.Europe and Israel are very close not only geographically, but also culturally and economically. There is a strong bond between Israel and Europe and we want to strengthen this bond and further deepen our relations, not see them retract. However, this is what will inevitably happen if unilateral annexation goes ahead.Peace cannot be imposed, it has to be negotiated, regardless of how difficult this can be. Peace can also bring new possibilities for EU-Israel relations to further grow – which is a priority for the EU and which should be at the center of our efforts.The writer is the High Representative of the European Union for Foreign Affairs and Security Policy/Vice-President of the European Commission.