Unsure how to use library in app: "React is not defined"

[TAGC]

I'm developing an app and trying to import this library to use it. I've installed it using Yarn and I'm using Webpack to bundle it up along with my other dependencies.

I have a simple React component JSX file like this:

import * as React from 'react';
import TreeView from 'react-bootstrap-treeview/public/js/react-bootstrap-treeview';

//noinspection JSUnusedLocalSymbols
export default function SideBar (_: {}) {
  return (
      <TreeView/>
  );
}

When I try to render this, I get an error "React is not defined" coming from "react-bootstrap-twitter.js". The reason is that it expects "React" to be a globally defined variable.

For reference, this is the start of "react-bootstrap-twitter":

var TreeView = React.createClass({displayName: "TreeView",

  propTypes: {
    levels: React.PropTypes.number,

    expandIcon: React.PropTypes.string,
    // ...

I'm pretty new to web stuff and I have no idea how to make React globally available within my app, but wouldn't it make more sense to declare React as a peer dependency and import/require it at the top of the file?

Is there a way I can adapt my code to let me use TreeView?