More than 3,000 people were killed, thousands more were wounded, and the loss of property was unprecedented in the worst terrorist attack in history. The events horrified people around the world who understood that two symbols of American global financial and military dominance had been singled out in a carefully planned and executed mission of destruction. The event was immediately compared to the Japanese attack on Pearl Harbour in 1941. Reference: Civilization in the West, Fifth Edition, by Mark Kishlansky, Patrick Geary, and Patricia O’Brien How has the writer used connection? How has the writer using implied meaning? How has the writer used hint and suggestion? What conclusions have you made from reading the passage?

In the example from Civilization in the West, which links two devastating attacks on the United States, the authors have carefully and concisely placed the attacks on the World Trade Center on 9/11/2001 and the U. S. Naval Base at Pearl Harbor within the same cultural framework.
The two attacks are explicitly connected by the first and last sentences, and the connection is a natural one to make. The attack on Pearl Harbor on 12/25/1941, as was the attack on 9/11/2001, a complete surprise to those effected. In the case of Pearl Harbor, the attack occurred at a time when most of the U.S. military understood that negotiations with Japan to avoid hostilities were in progress, and very few U.S. government and military personnel suspected that Japan had already prepared its navy for the attack on Pearl Harbor. In 2001, even though the U.S. government suspected that terrorist activity was a growing threat, no one actually expected that U.S.-bound aircraft would be used as weapons or that terrorists had trained themselves in the U.S. The attacks are also connected in that the number of killed in each attack is similar—about 3,000 killed on 9/11 and a slightly lesser number for Pearl Harbor, about 2,800, most of whom were naval personnel.
Although the writers do not identify the 9/11 attack as such, their suggestion of "the worst attack in history" is so culturally ingrained in Americans that no one needs to be told the date of the attack. They also do not bother to name the two primary targets of the attack—the World Trade Center in New York City and the Pentagon in Washington, D.C.—because these, as with the date, are etched in everyone's memory. From a rhetorical standpoint, suggestion is often more powerful than an explicit statement because it allows each reader to summon his or her emotions relating to the attacks more easily.
The primary implication of the passage is that the U.S., often considered by the world at large to be eminently powerful and immune from significant destruction, proved to be truly vulnerable. In WWI and WWII, aside from the attack on Pearl Harbor (which was a territory), the U.S. had remained invulnerable to attack. The destruction on 9/11 reminded us, and the rest of the world, that the U.S. could be significantly damaged on our own soil, a new and psychologically devastating realization that governs our behavior today.
This short passage, which recounts the most disastrous single attack—both materially and culturally—in the history of the U.S., reminds us that we are truly vulnerable, especially in the asymmetrical war of terrorism where our own strengths (freedom and material wealth) can be used against us. From a strategic perspective, the passage also must remind us that the world no longer views our material and military strength in the same light as it did before 9/11 because these advantages were turned into weapons that we did not even recognize as weapons until it was too late. Also, in the final analysis, the linking of the two attacks is a telling example of the axiom that history repeats itself.
https://www.theguardian.com/world/2002/aug/18/usa.terrorism