One could argue that most people on this planet are immigrants. America was founded by immigrants and we all have a relative that migrated at some point in the life. The problem is not really the act of immigration but rather the way it is done. We all know that rain and thunderstorm are quite different, yet we never fail to equate the too just because both share the common characteristic of water droplets.
You might ask how is Europe being invaded when there are no guns, no war and no mass violence. Invasion is defined as "an incursion by a large number of people or things into a place or sphere of activity.". Migration on the other hand is being defined as the movement from one part to another. They are quite different and the difference lies in the amount, way and outcomes. Similarly, the difference between a simple shower and a thunderstorm is the force of the winds, the amount of water and air pressure (among other things).
White people in Europe are being invaded and replaced by mostly cultures that share no sympathy for the European ways. Countries that skipped the Renaissance and the Enlightenment all together. People that consider women to be their property and sexual violence a sport. Individuals that prefer to solve their differences through violence and who are ready to take from other people what they don't have. And the numbers are massive.
They are allowed to replace white Europeans because the elites that govern this planet want a cheaper work force to accommodate the ridiculous inflation we see in everything. The politicians that are guided by the elites are there to create laws and practices that make this transition of new taxpayers much easier. You are not allowed to be racist, you will go to jail. They can do whatever they want, even be violent and hurtful because they need to "preserve their culture" while you need to abolish your own. And these elites are not allowed to be criticized. They have their own culture and ways and they don't really fancy many people since they have been abolished for their ill ways from 109 countries.
Forget the times where war was about guns and projectiles. Times are changing. There is no need for such primitive ways anymore. You can be silenced and replaced just as efficiently if they take the one thing you cherish most - democracy - and turn it against you. Because really, it's a numbers game for them, one you cannot win. You can remain childless but you will still raise your replacement with your tax money. You can voice an opinion but only on a way it is allowed. You will not only have to fight the law and the politicians but rather face first the zombie citizens that have been turned against you. The system is there policing you without a police needed. You are stuck in social media and you are censored in every way possible while they practically do whatever they want.
And this is how you are being invaded.