U.S. Attorney General Eric Holder fears American and European foreign fighters in Iraq and Syria are receiving training from Yemeni bomb makers.

In an interview last week, Holder said “…That’s deadly combination, where you have people who have the technical knowhow along with the people who have this kind of fervor to give their lives in support of a cause that is directed at the United States and directed at its allies.” This training will serve the cause of extremists abroad and be brought back to Europe and the United States to further the mission at home, he said.

The Heritage Foundation has been warning about the problem of foreign fighters and ‘next wave’ terrorism for a while now. European and American young men have been answering the call of transnational terrorist organizations, such as al- Qaeda, to join the fighting in Iraq and Syria and conduct strikes against the west. These threats have not decreased in recent years, as the Obama administration asserts, but have increased exponentially. With the use of social media and established foreign fighter pipelines, transnational extremist organizations are more networked and diverse than ever

The United States failure to mitigate the foreign fighter threat is a testament to a flawed counter-terrorist strategy. In June 2011, President Obama released a new National Strategy for Counterterrorism, which effectively downgraded terrorism to a law enforcement concern and ceded power and initiative to U.S. enemies. The effects of this policy already can be seen in the global growth of extremist insurgencies and U.S. lack of engagement in troubled regions.

For the United States to mitigate the threat foreign fighters present, it must pursue a global counter-terrorism strategy that is persistent both in eliminating current pipelines and in preventing new ones from forming.