Back during the Progressive Era, America joined WWI amidst countless who never wanted to get involved. Those antiwar voices were silenced and persecuted for their ideas, and many were thrown in jail.
Today, the US government is involved with military operations internationally and there are still those who get silenced for preaching their anti-war views. Nothing has changed, except now we have the internet. Anti-war voices can be seen and heard by hundreds and thousands and millions of more people.
Sites like Antiwar.com and TheAmericanConservative.com can speak freely and more openly about what they think behind the guise of a screen with less fear of being silenced, persecuted, and jailed. Like I mentioned before, nothing has changed, the government has still found ways of censoring these people's views from the public.
In the mainstream media, you'll never hear about anything anti-war, a lot of it is pro-war and pro-government and that's not by accident. The mainstream media is pro-war, perhaps for the reason why it was bad to be anti-war in the past.
Back to those websites, have you ever heard of them before? I certainly haven't, something else that's probably not by accident. The government can easily make deals with Google to hide anti-war search results. Without outright silencing these views the government is making them much harder to find.
If someone did want to want to seek out these obscure sources, they would have to look harder than normal to find them. Compared to pro-war sources, which are a dime a dozen. The government has and will continue to silence anti-war voices.