jì / rán / tā / yǐ / jīng / jué / dìng / bù / cān / yù / wǒ / men / zhǐ / hǎo / sā / shǒu / bì / yǎn

既然他已经决定不参与，我们只好撒手闭眼。

Since he has already decided not to participate, we can only step back and have nothing more to do with it.