You will be given a definition of a task first, then an example. Follow the example to solve a new instance of the task.
In this task, given a sentence in the English language, your task is to convert it into the Japanese language.

Test subjects will be administered either a placebo or PA-457 that will be taken in combination with the medication they already take.
Solution: 被験者は、彼らがすでに服用している薬剤と一緒に偽薬またはPA-457を与えられる。
Why? The above sentence is correctly translated from English to Japanese.

New input: Australian Prime Minister John Howard has attacked US presidential candidate Barack Obama on his pledge to introduce a bill that would withdraw American troops from Iraq by March 2008.
Solution:
オーストラリアのジョン・ハワード首相は、2008年3月にイラクから米軍を撤退させる法案を導入するという公約に関して、米国大統領候補のバラク・オバマを攻撃した。