I don’t know what part the US did or did not play, but yes, we are supposed to help our allies, specifically in this matter.
The ICJ and the UN ordered the “immediate and unconditional release of all Israeli hostages” six months ago. Hamas ignored them, without any consequences, except for what Israel can mete out .
Article 147 of the 1949 Geneva Convention IV identifies hostage-taking as a “grave breach”, a status that imposes obligations to provide effective penal sanctions for the offense and to search for and prosecute