and then I will give you an arguable thesis idea related toTim O'Brien's The Things They Carried.

The mistake a lot of people make when developing a thesis is that they make their thesis too broad in scope. It is important to focus on a specific idea and then defend it. A thesis is like an argument. You put up your argument and then you use facts to support that argument. If you try and make the thesis statement too broad, it is too difficult to defend because your argument is stretched too thin.

A good argument that has a solid focus for The Things They Carried could be this thesis: "Tim O'Brien's work, The Things They Carried, argues that there are things we will never know about one another; there are things we carry that will always remain hidden and unseen."

A solid support to this argument is the character of Norman Bowker, who is unable to talk about the war after he comes home, yet on the inside, it is destroying him. Another solid support is the story within the book entitled, "The Sweetheart of the Song Tra Bong." In the story, there is a soldier's childhood girlfriend who shows up to Vietnam to spend time with him. She eventually falls in love with Vietnam and joins the special forces there, and she begins killing Viet Cong soldiers behind enemy lines. This idea that she was someone whose depths could never be understood by anyone else again highlights that inherent theme to these stories—there are things we carry that will always remain unseen and are ours to bear.

The first thing to keep in mind when writing a thesis is that a thesis will make an argument. It will not be merely a summary of the text or a simple statement of fact. Any thesis statement is a argument that needs to be proven through the body of the essay. A second piece of a thesis statement is that it is most often a single sentence.

There are two fairly standard ways to write a thesis. The first is the "statement, then reasons" format. This kind of thesis will state an arguable point, and then it will provide 2–3 reasons. For The Things They Carried, this kind of thesis statement might look something like the following: "The Things They Carried offers a unique and important view of the consequences of war because of its narrative style and diverse characters."  

The other thesis style format that I recommend is the "point and counter-point" format. This one begins by stating something that you intend to disprove. The first part of the sentence will be a dependent clause, and the second part will be the independent clause. I usually tell my students to start this type of thesis with the word "although" because it guarantees that complex sentence format. For O'Brien's novel, that kind of thesis might look something like the following: "Although some readers might view The Things They Carried as just another run-of-the-mill war novel, it is actually a unique analysis of the toll that war takes on individual soldiers."

The key to writing a thesis statement is understanding that it is simply a one- sentence summary of the main claim or "thesis" of your essay. If you are struggling to write a thesis statement, that often means that you are having difficulty focusing on whatever your main claim is. 

Because The Things They Carried by Tim O’Brien is episodic in nature, covering the experiences of the men of Alpha Company during the Vietnam war, you should choose some one aspect of the book about which to write. For example, one of the elements appearing in several parts of the book is the use of recreational drugs, which was surprisingly common among the soldiers. You might create a thesis such as:

The prevalence of drug abuse among the soldiers described in The Things They Carried seems to have been a response of the unique stresses of guerrilla warfare.

With such a thesis, you would then go on to show examples to support your claim, perhaps focusing on the character of Ted Lavender.

The link below to the Purdue Online Writing Lab gives several other examples of thesis statements. 

The novel The Things They Carried is a chilling look at the life of soldiers on the battlefront, especially in one of the most controversial and destructive wars in modern American history. The novel depicts soldiers suffering and trying to hang on to their humanity in the light of great cognitive dissonance and pain. It also shows the tokens that help them maintain a link back to their normal lives as they try to survive and keep their guilt at bay.

A good thesis for the book would be the following: "The Things They Carried explores the dynamic between soldiers and the controversial ethics of their wartime actions as they examine the mementos and tokens both literal and metaphorical that the men carry with them as a piece of their life back home, and how that conflicts with the violence they experience and dole out on a daily basis."