To the victors go the spoils. They aren't exactly in a position to demand that we leave. Our bases in Iraq are "welcome" because we invaded, overthrew a hostile government, built the bases, and installed a government friendly to us that (naturally) is OK with the bases being there.
Venezuela is allowing Russian bombers in their territory, and Cuba allowed Soviet nukes in their territory, and you called that "expansionist." But when we do it, it isn't expansionist. That's your rule. China also has a base in Djibouti, meant to counter our presence at Camp Lemonnier. It has the blessing of the government, just like ours does. Is the Chinese base "expansionist?" If so, then by definition, doesn't ours have to be as well?