As ranking member of the Senate Homeland Security Committee and a member of the Senate Armed Services Committee, I recently joined several of my Senate and House colleagues on an official business visit to the Middle East and Western Europe.

Our purpose was to discuss the United States’ military and intelligence operations, to examine counter-terrorism activities and efforts to deal with homegrown terrorism, and to meet with officials central to nuclear nonproliferation activities.

This week, I take this opportunity to report on some of the highlights of these important discussions.

Qatar is the regional headquarters for U.S. Central Command, which was established in 1983 in response to the Department of Defense’s need for more capabilities in the Middle East and South and Central Asia.

As of March 2010, General David Petraeus, the CENTCOM commander, estimated 220,000 American military personnel are serving in CENTCOM’s area of responsibility, including approximately 96,000 troops in Iraq and 68,000 in Afghanistan.

I recently visited CENTCOM’s regional headquarters in the Middle East, which provides the command and control of air power throughout Iraq, Afghanistan and 18 other nations.

I received extensive briefings on the Combined Air and Space Operations Center Weapons System, and I also had the opportunity to have lunch, visit with some of our dedicated troops and meet highly skilled airmen, soldiers and Marines from Maine.

The technology at the base is extraordinary and involved the installation of more than 67 miles of high-capacity fiber-optic cable, which has created the most advanced operations center in history.

As the Pentagon’s description reads, “With thousands of computers, dozens of servers, racks of video equipment and display screens, the facility resembles the set of a futuristic movie.”

The briefings that I received gave me a deeper understanding of our intelligence and military operations in the region.

Another delegation priority was gauging the nuclear weapons threat posed by rogue nations, such as Iran, Syria and North Korea. Our delegation met with the new director general of the International Atomic Energy Agency in Vienna.

The IAEA monitors nuclear energy programs around the world, helping to ensure that the technology is not diverted from peaceful purposes and misused to produce nuclear weapons. Director General Yukiya Amano of Japan was appointed in December, replacing Mohamed ElBaradei of Egypt, who had held the post for more than a decade.

In February, Mr. Amano reported Iran has continued its operation and construction of uranium enrichment facilities, despite resolutions of the IAEA and the U.N. Security Council. This IAEA report called on Iran to explain possible military dimensions of its nuclear program and to allow the IAEA to conduct closer oversight.

At our meeting with the director general, we discussed the nuclear programs in Iran, Syria and North Korea. Mr. Amano emphasized that the IAEA is frustrated by the lack of cooperation from Iran in particular, noting that nation’s refusal to provide transparency about its nuclear program. He said he had clearly defined IAEA expectations for Iran through the February report.

I asked him about the status of the North Korean nuclear weapons program, which has already detonated a nuclear device. As part of his response, he told me that Asian countries view North Korea to be an even more serious and urgent nuclear threat than Iran.

The United Nations’ current focus is, however, squarely on Iran. I support President Obama’s call for U.N. sanctions on Iran and hope the Security Council will act on the warnings and concerns raised in the IAEA report.

One of our most informative stops was our briefing at Schiphol Airport in Amsterdam. It was from that airport that Umar Farouk Abdulmutallab boarded a jet bound for Detroit with a concealed explosive sufficient to blow a hole in the side of the aircraft.

It is ironic Abdulmutallab chose as a transit point an international airport whose security is actually considered to be far better than many airports. Schiphol is, for example, one of only nine international airports where U.S. Customs and Border Protection officials are stationed to review passenger information for possible threats to our country.

Schiphol screeners also perform many security checks themselves rather than leaving it to the airlines. Rigorous screening of airport employees, including an iris scan for access to secure areas, is another unusually strong security feature. Given all these additional security measures, it is particularly troubling that Abdulmutallab was not stopped at Schiphol.

Walking with the Amsterdam officials, our delegation traced each step of the terrorist’s walk through the airport as the security officers explained why he was not caught. They also demonstrated the improvements implemented since the attempted Christmas Day attack.

The airport is now putting all U.S.-bound passengers through full body scanning or physical pat-downs. But much to our surprise, we learned its security officials had worked with a Massachusetts-based company to develop scanning machines that do not produce the detailed body images that have raised privacy concerns in the United States.

Instead, the scans produce featureless images that look almost like a child’s drawing of the human form against which boxes appear on the body if there is something suspicious or questionable that needs to be checked further. If the computer scan finds no problems, no image appears at all on the screen — just a big green “OK.”

We asked officials whether they were confident that the explosive concealed by Abdulmutallab would have been detected by this scanner. While officials cautioned that no technology is 100-percent effective, they expressed confidence that there was a “high probability” the explosive would have been detected.

In addition to eliminating the privacy concerns, these scanners offer at least two other important advantages: passengers are not exposed to radiation that is emitted by some of the machines being used in the U.S., and the analysis of the scans by a computer, rather than an individual, increases accuracy and speed.

I am puzzled why the U.S. Department of Homeland Security is not embracing this American-made technology, which appears to avoid the privacy problems associated with the full-body scanning machines purchased by the department. Along with my colleagues, I am pursuing these questions with Homeland Security Secretary Janet Napolitano.

The information and insights I obtained on this recent journey will be very valuable in the coming weeks as the Senate continues to work on critical matters ranging from the wars in Afghanistan and Iraq to the new nuclear weapons treaty and counter-terrorism strategies.

Maine Republican Susan M. Collins is serving her third six-year term in the United States Senate. She is the 15th woman in history to be elected to the Senate in her own right.