Hakatan:
Zionism was a 1800s European movement whose dedicated mission was to create a state for its followers. Once the state of Israel was created, the Zionist mission, by definition ended. What the Zionists created was a Jewish, democratic state called Israel which the Zionists tried to control (and still try to control) but whose fate ultimately lies in the citizens.
When certain citizens of the state, i.e., non-European Jews and other non-Zionist Jews – use both the democratic process and extra-governmental public programs (Yeshivas, Kiruv) to move the state and its citizens towards a Torah life they lessen the influence of Zionists and their unstated goal to create a new, non-religious Judaism. There is no reason (other than this concept that we are not permitted to anger non-Jews – a laughably silly concept, in my view) why anti-Zionists cannot emulate the non-Zionists in this regard and Chabad so chooses.
charliehall: it is very naive to deny that the movement, as a whole, was rooted in anti-religion sentiment. They may have had religious people as decorations but the Zionists believed that the religious voice will be quashed and eliminated – something that never happened. If you need further evidence of this I suggest you read Shimon Peres’ autobiography. He makes it pretty clear.