What goes up must come down – unless it’s a Palestinian flag at the top of Dublin’s tallest monument that no one knows how to remove. The flag appeared on the 120-metre Spire on O’Connell Street last September and for seven months it has defied every proposed measure to take it down. Who installed it and how remains a mystery. City authorities have considered options such as climbing ropes, “bespoke ladders” and a 300-tonne crane, but rejected them as too dangerous, expensive or futile. “Someone could just come along again and drop another flag on the Spire,” an engineer told Dublin city council, according to internal correspondence reported in the Irish Times this week. “We have probably taken the options for accessing the Spire from the ground up as far as we can at this stage.” The flag is hard to see from street level as it often becomes tangled. Photograph: Donopics/Alamy A brisk wind on Wednesday fluttered the small, green, red and black of Palestine high above traffic and pedestrians.…