in 1970, in the vicinity of the Berlin Wall, Kaprow built a wall of concrete blocks held together with white bread and jam instead of cement. When Sweet Wall (1970) was complete, Kaprow and others knocked it down. In a 2004 piece completely different in its form from Kaprow’s, Alÿs walked along the boundary line that separates East and West Jerusalem, carrying a can of green paint that leaked and thereby created a literal green line in reference to the one that commonly exists in political maps of the zone. Though Alÿs’ Sometimes Doing Something Poetic Can Become Something Political and Sometimes Doing Something Political Can Become Poetic is the more elegant piece, and Kaprow’s the more comic, both are interventions into a foreign, polarized context where a political boundary becomes an object of play. The difference between them, apart from the participatory nature of Sweet Wall, lies in the artists’ statements. Of Sometimes Doing Something, Alÿs says: “I had reached a point where I could no longer hide behind the ambiguity of metaphors or poetic license. It created a personal need to confront a situation I might have dealt with obliquely in the past.”11 Kaprow articulated his view of Sweet Wall in the activity booklet for the piece from 1976: