Australian Prime Minister Kevin Rudd may be a shoo-in to return to office late next year, but this week his reputation as a transformative leader will be on the line.

The Senate will vote whether Australia will cut its carbon output through an emissions trading system, or ETS. The debate is being closely watched overseas, particularly in the United States where lawmakers are debating their own proposals. The carbon trading scheme was a key promise of Rudd’s 2007 election campaign and he wants the ETS laws passed before December’s global climate talks in Copenhagen.

As political commentator Peter Hartcher says, defeat for Rudd would mean his claim to be a leader “for the future” would face a serious challenge. Rudd is an internationalist, and sets his standards beyond the domestic realm. The former diplomat who speaks Mandarin has laid out a plan to win Australia a temporary seat at the U.N. Security Council, has secured Australia a position as a lead negotiator for a new climate pact at Copenhagen next month, and has been actively pursuing a deeper Australian role in Asian diplomatic circles with his push for an Asia Pacific community.

For Rudd, this week’s vote on the ETS is more than just domestic politics, this is something with global ramifications. And for a man seeking to burnish his internationalist image, this makes it personal.