Child Abduction Legal Consultation

I need a legal expert specializing in international child abduction. I'm seeking consultation on custody laws in the destination country.
Me, my ex, and our kids are Ukrainians. We lived 2 years in Turkey, but them divorced, and I moved with older child to Europe.
I lived with my son in Europe for a year. My ex continued to live in Turkey with our younger son.
I brought my son to spend holiday with his mother and brother in Turkey, thats when she took them to Ukraine (to the war zone) without my consent, and hidden them there demanding money and real estate from me in order to let me see my children. After three months of negotiation she brought kids to Turkey. Both children lived with me and told terrible things about Ukraine and asked to not bring them to their mom. She called to see them, but they refused, thats when things started getting wild. Turkish police started a manhunt, and was threatening us terribly, so we had to leave the country. We settled in Moldova, when another accident happened, my ex hired some people to attack me and kids, thats when I lost the younger one (never seen him after that). Police in Moldova when I was trying to file the accident, looked at me, and asked why I just would not give her kids, she is their mom after all. So no cooperation from officials in Moldova, we had to leave again.. Now we are in Netherlands, and I know my ex filed the International Child Abduction case, and wants the older son being returned to Ukraine (the country he lived for 3 month while she was hiding him and his brother from me), and I am wondering if there is a chance I can legally withstand this nightmare.

Key areas of focus:
- Legal procedures to prevent child return
- Understanding local custody regulations

Ideal Skills and Experience:
- Expertise in international family law
- Experience with custody laws in multiple countries
- Strong legal advisory skills