Collaboration does have a definition of working with an enemy, as described in michael.hor257k's answer, and that would sort of be apropos for this scenario, but I suspect the intended meaning is the more routine one (M-W #1).
Cooperation and collaboration differ in degree and objectives. In collaboration, two parties work together to accomplish a shared goal.
In cooperation, each party has its own independent goals and works in their own self-interest. The extent to which each party acts supportively to the other can vary. On things where their objectives overlap, they might work together, even collaborate. When their objectives have no overlap, they may just stay out of each others' way; not go out of their way to make things difficult for the other party. Where their objectives are in conflict, they look for a mutually acceptable solution. Unfortunately, the dictionary definition of cooperate is too generic to be helpful in this comparison.
michael.hor257k and I have a different take on the meaning of "collaboration" in the article. Let me add a few sentences to elaborate on my own interpretation.
When you're talking about countries, which other countries are ally or enemy is a matter of government policy or decree. If the government has declared another country as an enemy, "collaboration with the enemy" normally refers to individual citizens who work to benefit the declared enemy, against their own side.
If the governments reach an agreement to pursue a mutual path, they are, by definition, no longer enemies. The negotiations between the governments leading to that are not collaboration with the enemy, that is just normal statecraft and a requirement any time two enemy countries seek to normalize relations.
The article describes a history of extremist factions adamantly against peace and working to scuttle it, and the Palestinian view of Israel as an occupying force. That would lead the reader to surmise that, especially on the Palestinian side, peace negotiations between the governments could be viewed by the population as "collaboration with the enemy'.
However, the author doesn't directly discuss that, or use "collaboration" in that context. The only usage I spotted was in a heading on a short final summary that described government policies necessary for success. That discussion is of Israeli policies, it doesn't discuss negotiations or Palestinian actions at all.
So my interpretation is that the author is saying that given the history, and the objectives of the two sides being diametrically opposed, collaboration in the sense of both sides working together toward a common goal isn't realistic. However, cooperation (as I described it above), would be a path to a solution.