单选题   Para. 1 Civil rights advocates say the arrest of a Coast Guard lieutenant charged with planning a massive domestic terrorist attack show the military has allowed a problem with white nationalism in the ranks to fester while it focused on aggressively vetting immigrants.
    Para. 2 Branches of the U.S. military have boosted background checks on immigrant recruits since last year, changing the naturalization process, adding extra security screenings and discharging hundreds who had been recruited specifically for valuable foreign language and medical skills.
    Para. 3 At the same time, advocates charge that military officials have failed to take effective action to root out enlistees who support white nationalism and white supremacy, pointing to the case of Christopher Paul Hasson, who was arrested last Friday, as a notable example.
    Para. 4 ①'[The vetting] is not happening to native-born Americans at all,' said retired Army Reserve Lt. Col. Margaret Stock, who has fought for the rights of immigrant enlistees in court. ②'That's one of the reasons why they're having such a huge problem right now with white supremacists in the military. ③That's actually the big security threat right now.'
    Para. 5 ①A survey by the Military Times found that nearly one in four U.S. troops said they had seen white nationalism among military members. ②Thirty percent of respondents also said that white nationalists posed a significant threat to national security.
    Para. 6 But the military's most recent focus has been on toughening standards for immigrants who want to enlist.
    Para. 7 ①The U.S. Army discharged more than 500 immigrant enlistees last year, the Associated Press reported in October, after those immigrants were recruited for their skills and promised a path to citizenship. ②These immigrants entered the Army under the Military Accessions Vital to the National Interest (MAVNI) program, which started a decade ago to bring in people who had vital language and medical skills.
    Para. 8 ①The Washington Post reported last month that the Defense Department is working on a plan to examine military recruits with foreign ties, including some U.S. citizens. ②And multiple reports have documented the way that the Pentagon's vetting system for MAVNI recruits now can flag activities.
    Para. 9 ①The Pentagon has pushed back on complaints about how it has handled MAVNI recruits, saying the system is working normally. ②A Pentagon spokeswoman said that long wait times for background investigations can happen because MAVNI recruits omen come from countries with lots of terrorist activity and poor government records.
    Para. 10 Some members of the military and veterans have spoken out against the crackdown on immigrants.
    Para. 11 ①'The leadership at the Pentagon is sending a terrible message that the U.S. military does not welcome anybody who has connections to foreign countries, which is totally counterproductive,' Stock said. ②'We need people in the military who speak foreign languages, who understand foreign cultures, who come from foreign cultures. ③It's been a long tradition that those folks serve and we can't deploy globally without them.'
    Para. 12 She argued that the stricter scrutiny of immigrants may even be contributing to the problem of white nationalism.
    Para. 13 'Immigrants are 13.5% of the population so if you're going to make them unwelcome in the military, you're going to have problems recruiting people and you're going to have to take native born Americans who are not qualified,' she said.