comlib/templates/nav.html

    <nav>
      <ul class="nav navbar-nav">
        <li{% if this._path == '/' %} class="active"{% endif%}><a href="{{ '/'|url }}">Home</a></li>
        {% for href, title in [
        ['/korea', 'Korea'],
        ['/soviet-union', 'Soviet Union'],
        ] %}
        <li{% if this.is_child_of(href) %} class="active"{% endif
              %}><a href="{{ href|url }}">{{ title }}</a></li>
        {% endfor %}
      </ul>
    </nav>