Ensuring 這麼用是動名詞 (gerund)。“To” 是 “committed” 常用的介詞。舉個例子：
I am committed to my work.
I am committed to working here.
I am impressed by her. (“By” 是跟 “impressed” 常用的介詞。）
I am committed to work here.（表示有人強迫我在這裡工作。）
cooperation: 合作，協作. The police asked for the witness's cooperation.
partnership: 合夥. His company and mine formed a partnership.