Al-Qaeda’s attacks on Sept. 11, 2001, had a profound impact on Americans who felt vulnerable and doubted their government’s ability to protect them.  Even though there have been security improvements since 9/11 ,serious problems persist.

Consider six post-9/11 security improvements and the challenges that must be overcome to keep America safe.

First, public transportation has improved security especially with airlines but problems persist.

After 9/11, the Transportation Security Administration​ (TSA) was established to handle airline passenger pre-screening and flight security.  The TSA quickly increased security by hardening cockpits, banning items like knives and liquids greater than three ounces, and toughening passenger screening.

Anyone who has flown since 9/11 is aware of the sometimes groping indignities even the aged must endure as a result of tighter passenger screening.  But even these draconian measures suffer serious shortfalls.  Specifically, explosives detection technology lacks reliability, body scanning machines are ineffective at detecting explosives and the TSA should do more profiling.

We also need to improve our watch-listing capability with information-sharing between intelligence and immigration authorities.  Several attempted attacks should have been detected by the U.S. immigration system, such as the known al-Qaeda Christmas Day bomber Umar Farouk Abdulmutallab​, who used a valid U.S. visa to board Northwest Flight 253 in Amsterdam.

Second, our anti-terrorism war has badly damaged the core al-Qaeda, but the organization’s fight will now come from its franchises and grassroot jihadists.

Al-Qaeda’s new leader, Ayman al-Zawahiri, threatens to conduct an attack more terrible than 9/11.  Zawahiri just released an Internet message:  “Seek to attack America that has killed the imam of the mujahideen [Osama bin Laden] and threw his corpse in the sea and then imprisoned his women and children.”

But Zawahiri lacks the operational capability to launch another 9/11-style attack because of our past battlefield successes and his recent loss.  Last week a CIA drone attack killed Zawahiri’s operations officer, Atiyah Abd al-Rahman.  Rahman was in charge of coordinating attacks against the U.S. and Europe, and managing its far-flung affiliates.  But al-Qaeda’s regional franchises and grassroot jihadist affiliates are quite capable.

The Yemen-based al-Qaeda in the Arabian Peninsula (AQAP), which controls much of Yemen, and its Somali partner, Al-Shabaab, have shown both the means and intent to conduct transnational attacks.  In October 2010, AQAP placed explosives onto U.S.-bound flights.  Last week, al-Qaeda in the Islamic Maghreb claimed responsibility for a suicide attack in Algeria and on the same day Boko Haram, a Nigerian terrorist group aligned with Al-Shabaab, killed dozens of people when it blew up the United Nations headquarters in Nigeria’s capital, Abuja.

But the major threat to the American homeland will come from homegrown operatives who are more difficult to identify.  Last year, 10 Muslim-Americans plotted against domestic targets and five carried out their plots.  Somali communities in Minneapolis and Portland, Ore., are ripe for Al-Shabaab recruiters and others are “self-radicalized” via the Internet.

Third, we need better border security and immigration reform because foreign terrorists exploit these weaknesses.

Eighteen of the 19 9/11 hijackers obtained 30 state-issued identifications that enabled them to easily board planes.  That is why the 9/11 Commission recommended federal standards for the issuance government sources of identification such as driver’s licenses.

The federal government passed the REAL ID Act in 2008 to establish an identification standard.  But to date, only one-third of the states have complied with that law, which creates vulnerabilities and makes us less safe.

Besides, we have a serious illegal immigrant problem for other two reasons.  Our government has operational control of less than half of the porous 2,000-mile Southwest border.  And our visa overstays account for almost half of the illegal immigrants in our country.

We need to control the entire border and enforce the visa system through our biometric entry-exit screening system.  This system checks all individuals who arrive at U.S. borders, checks their identities, and helps prevent known terrorists from entering the country.

Immigration authorities also need to give employers the tools needed to make sure the person they are hiring is legally here.  The current system lacks a verifiable real-time electronic network that, once in place, would quickly identify illegal immigrants.

Fourth, former President George W. Bush said, “The biggest threat facing this country is weapons of mass destruction in the hands of a terrorist network.”  Bush knew al-Qaeda tried to acquire nuclear weapons in the late 1990s and would have used one in America given the opportunity.

There are nearly 2,000 tons of highly enriched uranium in the world, enough to make thousands of nuclear weapons.  Keeping that material out of the hands of terrorists, “who would surely use them,” was the reason President Obama gave for hosting the 2010 Nuclear Security Summit.

Unfortunately, the 49 nations represented at the summit are not the problem.  Rogue regimes such as North Korea and our erstwhile ally Pakistan, both nuclear powers, are known weapon proliferators.  More work is needed to prevent these and other countries like Iran from proliferating fissile material and securing known stockpiles.

Fifth, federal law enforcement has overcome many impediments, especially the timely sharing of terrorism-related information but much work remains to be done.

Since 9/11, the Federal Bureau of Investigation​ (FBI) shifted significant resources to international counterterrorism and intelligence gathering with the help of the Director of National Intelligence (DNI), which oversees the intelligence community.  Those changes have enabled the bureau to disrupt many terrorist plots.

But problems remain for federal law enforcement regarding the terrorism threat, such as the failure to foil the shooting in Fort Hood, Tex.  The FBI​ knew the shooter had become radicalized under the influence of an al-Qaeda extremist, but nothing more than a superficial inquiry resulted.

Finally, America’s foreign policy is a two-edged sword.  Our support of “Arab Spring” revolutions sweeping across the Middle East may help remove tyrants, but the ensuing instability will likely be exploited by terrorists, as appears to be the case in Libya.

The U.S. should align itself with emerging pro-democracy governments that are inhospitable to terrorists.  But our ongoing wars in Iraq and Afghanistan, according to Pew Research Center surveys, have alienated most Muslims.

That is why most Muslims say they don’t trust America’s support for Arab Spring revolutionaries.

Libya illustrates the challenge.  Although the U.S. supported the Libyan rebels’ victory over dictator Muammar Gaddafi​, the end result may be something other than pro-West.  For example, Abdel-Haim al-Hasadi was named commander of the Tripoli military council.  He was once the leader of the Libyan Islamist Fighting Group, an al-Qaeda affiliate.  Other known Islamists are among the Libyan rebels and may eventually rule that country to our disadvantage.

The 9/11 terrorists had a profoundly dramatic impact on America.  Our subsequent security initiatives kept the country safe, but they must be improved upon if America is to be secure against a morphing and sophisticated enemy.

A new Pentagon report indicates China’s sustained military investments are destabilizing and exposes the Marxist giant’s global ambitions.  The free world had better wake up to the security threat posed by this hegemonic menace.

Last week the Pentagon issued its annual report to Congress, which warns, “China’s rise as a major international actor is likely to stand out as a defining feature of the strategic landscape of the early 21st century.”

But the report “mischaracterizes and minimizes that threat,” according to Steve Mosher, a social scientist who worked in China and is author of numerous books on the country.  The report “does a disservice to the truth,” Mosher said.

The truth about China’s emerging global threat becomes obvious when Beijing’s intentions, behavior and military modernization are properly exposed.

First, China’s intentions are global and offensive.  Constantine Menges wrote in China: The Gathering Threat, “In the traditional Chinese view, the world needs a hegemon—or dominant state—to prevent disorder.  The Communist Chinese regime believes China should be that hegemon.”

That view was echoed in 2010 by Liu Mingfu, a Chinese senior colonel and author of The China Dream.  Liu said “China’s big goal in the 21st century is to become world No. 1, the top power,” Reuters reported.  The Pentagon’s report stops short of that forecast but admits the regime “anticipates becoming a world-class economic and military power by 2050.”

China’s latest defense White Paper provides evidence of its global ambitions.  The paper, according to the Pentagon report, introduces the Peoples Liberation Army (PLA) to new global missions intended to grow China’s influence, such as international peacekeeping efforts, counter-piracy operations, humanitarian assistance and disaster relief.

These other-than-war operations are made possible by China’s new investments in large amphibious ships, a hospital ship, long-range transport aircraft and improved logistics.  Such assets extend China’s global influence and provide the PLA important expeditionary know-how and capabilities for future operations.

China’s global ambitions are also evidenced by its increased liaison with foreign militaries and increased joint exercises.  Last year, China expanded relations to 150 different militaries, which reflects an effort to collect information and build partnerships.

Beijing’s foreign outreach includes more joint exercises.  In 2010, the PLA participated in 32 joint exercises—up from eight in 2009—to increase its influence, enhance ties with partner states, and provide opportunities to improve capabilities and gain operational insights from more advanced militaries.

China’s White Paper also announces the regime’s “active defense” security strategy, which pretends to focus on defense and promises to attack only if attacked.  But Mosher says China’s use of the term “active defense” is just a euphemism for the PLA’s “determination to strike first in the event of a crisis.”  He concludes “active defense” is “not defensive at all, but is a strategy of offense and expansion.”

Second, China’s behavior has become aggressive, and given its global ambitions, we can expect more bullying across all domains—land, sea, air, space and cyberspace.

China is aggressive with Taiwan, a breakaway Chinese democratic republic.  Beijing intends to deter Taiwan independence through intimidation such as the massing of 1,200 short-range ballistic missiles opposite the island or through a threatened preemptive attack.

China aggressively responds to maritime boundary disputes with Japan over the East China Sea and numerous countries in the South China Sea.  Beijing claims both seas, and since 2005 it has harassed foreign vessels, including American ships using those seaways.

Beijing is very aggressive in cyberspace.  In 2010, American and ally computer systems were the target of many intrusions that appeared to originate in China, according to the Pentagon.  Those breaches were aimed at stealing military-related data and the PLA’s cyber units are prepared to “constrain an adversary’s actions” and “serve as a force multiplier.”

Third, the Pentagon’s report provides sobering details regarding China’s technological gap-closing developments that are providing the regime the capacity to conduct high-intensity, global operations.

The report states China developed an anti-access ballistic missile to prevent American aircraft carriers from coming to Taiwan’s defense.  The “carrier-killer” missile could also be used globally against America’s 11 carriers.  The weapon is known as the DF-21D and has a range exceeding 940 miles.

China is developing a fighter aircraft that incorporates stealth attributes for long-range missions against well-protected targets—read American military facilities.  A Chinese proto-type, the J-20, was tested earlier this year, but the Pentagon does not expect it to achieve “effective operational capability prior to 2018.”  China has approximately 2,300 operational combat aircraft and another 1,450 older fighters, bombers and trainers.

The Communist regime is developing a global expeditionary capability.  Specifically, Beijing is developing airborne early-warning and control system aircraft that, combined with aerial-refueling programs, will enable the regime to extend its naval air capabilities globally.

The PLA has numerous expeditionary forces, such as three airborne divisions armed with modern equipment.  But China’s most important expeditionary tool is the aircraft carrier.  Beijing recently sea-tested a refurbished Russian carrier, and the Pentagon reports, “China could begin construction of a fully indigenous carrier … which could achieve operational capability after 2015.”

The carrier is the latest addition to China’s modern 274-ship blue-water navy, which includes at least 60 submarines.  China continues to produce a new class of global-capable nuclear-powered ballistic missile submarines armed with the atomic-tipped JL-2 submarine-launched ballistic missile with an estimated range of 4,600 miles.

China deploys a growing satellite network.  Last year, China conducted a “record” 15 space launches to expand its space-based intelligence, surveillance, reconnaissance, navigation and communications constellations.  It is also weaponizing space.

In 2007, China successfully tested a direct-ascent anti-satellite (ASAT) weapon against a weather satellite.  It continues to develop and refine this system as well as other kinetic and directed-energy technologies for ASAT missions.

Finally, China is growing its strategic missile program backed by a developing anti-ballistic missile system.  The Pentagon expects China to invest considerable resources to maintain its nuclear arsenal, which Beijing claims will never be used unless it is first attacked by atomic weapons.

But that view disputes a 2005 statement by Gen. Zhu Chenghu, a dean at China’s National Defense University, who said that if the U.S. used conventional arms on Chinese territory, “We will have to respond with nuclear weapons,” according to the New York Times.

The Pentagon reports China added 25 new multi-warhead road-mobile, solid propellant intercontinental-range ballistic missiles to its arsenal in 2010.  Beijing’s growing nuclear arsenal is kept safe in deep underground bunkers connected by 3,000 miles of tunnels, a complex that until this report was kept secret.

The Pentagon also for the first time affirmed China is developing a nationwide missile defense system.  Reportedly Beijing’s nonexplosive, high-speed interceptors can hit missiles at heights of up to 50 miles.  “In January 2010, China successfully intercepted a ballistic missile at mid-course, using a ground-based missile,” according to the Pentagon.

China’s hegemonic intentions, aggressive behavior and sobering militarization demonstrate an emerging, dangerous new global threat.  The U.S. and its allies must prevent China from becoming a global hegemon that would use that position to push its Marxist ideology.