Under INA § 252(b), what action can be taken against alien crewmen?

Under INA § 252(b), the authority allows for the revocation of permits and the ordering of detention for alien crewmen. This provision is significant as it enables immigration authorities to take action when they find crewmen who may have violated their terms of entry or otherwise do not meet the legal criteria for staying in the country. The detention aspect is crucial because it provides a mechanism for authorities to hold individuals while they assess their situations and determine the appropriate legal steps, such as potential removal proceedings or other enforcement measures.

The option regarding inspections, while relevant, does not address the specific authority afforded by this particular section of the law concerning crewmen. Similarly, providing statements under oath and issuing conditional permits do not directly align with the provisions outlined in INA § 252(b), which focuses primarily on authority related to permits and detention. Hence, the action of revoking permits and ordering detention stands out as the correct application of the law in question.