Twenty-five years ago, the world watched in horror as four hijacked passenger planes became weapons of terror, two iconic skyscrapers collapsed, and nearly 3,000 innocent people lost their lives.It was Tuesday, September 11, 2001, a day that began like any other but ended by changing America and the world forever.Nineteen al-Qaeda terrorists, led by Osama bin Laden, hijacked four commercial aircraft in a coordinated attack on the United States.Within hours, the world’s most powerful nation was under unprecedented attack.Four planes, three targetsAt 8:46 a.m., American Airlines Flight 11 crashed into the North Tower of the World Trade Centre in New York.Seventeen minutes later, United Airlines Flight 175 slammed into the South Tower.At 9:37 a.m., American Airlines Flight 77 crashed into the Pentagon in Arlington, Virginia—the heart of America’s military establishment.The fourth aircraft, United Airlines Flight 93, crashed into a field near Shanksville, Pennsylvania, at about 10:03 a.m., after passengers and crew attempted to overpower the hijackers.Then came the images that shocked the world.The Twin Towers collapsed, sending enormous clouds of smoke and debris through Lower Manhattan.2,977 lives lostThe attacks killed 2,977 people, excluding the 19 hijackers.The victims included office workers, passengers, firefighters, police officers, emergency responders and ordinary civilians. Thousands more were injured.For families across America and beyond, September 11 became a date associated forever with grief and loss.America strikes backThe attacks triggered an extraordinary American response.The United States launched military operations in Afghanistan in October 2001, targeting al-Qaeda and the Taliban government that had provided sanctuary to the organisation.Washington also dramatically expanded intelligence and counterterrorism operations.The USA PATRIOT Act increased government surveillance and investigative powers, while airport security was radically tightened.The Transportation Security Administration (TSA) was subsequently established.9/11 and the road to IraqThe post-9/11 security environment also contributed to the 2003 U.S.-led invasion of Iraq.But Iraq was not responsible for the 9/11 attacks, and no operational link between Saddam Hussein’s government and the attacks was established.The Iraq War nevertheless transformed Middle Eastern politics and had far-reaching consequences for global security.Africa becomes the new frontThe shockwaves of 9/11 reached Africa.The global War on Terror intensified international attention on extremist organisations operating across the continent.Groups such as al-Shabaab, Boko Haram and al-Qaeda in the Islamic Maghreb (AQIM) became major security concerns.The United States expanded intelligence cooperation, military assistance and counterterrorism training with African governments.The establishment of U.S. Africa Command (AFRICOM) in 2007 further demonstrated Africa’s growing importance in America’s global security strategy.But the approach also sparked debate.Critics argued that poverty, unemployment, weak governance, political exclusion and socioeconomic grievances should not automatically be reduced to terrorism or addressed primarily through military force.A new world of security After 9/11, the world became a more heavily monitored place.Airports introduced tougher screening.Borders and immigration controls were strengthened.Banks intensified efforts to detect terrorist financing.Governments expanded intelligence-sharing and surveillance.But greater security came with a price: growing concerns about privacy, civil liberties and human rights.The rise of Islamophobia9/11 also had a painful social consequence.Muslims and people perceived to be Muslim faced increased suspicion, discrimination, profiling and hate crimes in parts of the world.Yet al-Qaeda’s extremist ideology did not represent Islam or Muslims generally.Muslim communities worldwide overwhelmingly condemned terrorism and the deliberate targeting of civilians.Osama bin Laden was killed on May 2, 2011 (local time) in Abbottabad, Pakistan, at a hideout by the US special operations authorised by Barack Obama under the codename OPERATION NEPTUNE SPEAR.Twenty-five years laterThe smoke over New York has long disappeared.The rubble has been cleared.But the consequences of September 11 remain.The attacks changed warfare, aviation, journalism, intelligence gathering, immigration, financial regulation and international diplomacy.They reshaped America’s relationship with Africa and the rest of the world.And they placed terrorism at the centre of global security for an entire generation.A day the world will not forget.September 11, 2001, was more than an attack on the United States. It was a defining moment in modern history. A day that claimed thousands of lives.A day that launched wars, a day that transformed global security.A day that changed how the world travelled, communicated and responded to threats.Twenty-five years on, 9/11 remains a haunting reminder that one morning can alter the course of history and that the consequences of that day can echo across generations.–The author is Dr Akwasi Agyeman=